I don't know if anybody has ever bothered to put up a recommended set of options for a "standard" AtB campaign (as the idea is you play the kind of game YOU want to play), but here's a list to get you started.
General tab:
Enter your unit's name
Choose the InterStellar Ops rules for rating
Choose your start date
Choose your camo
Go to the Against the Bot tab:
Check the "Use the Against the Bot campaign rules"
Click the "Set AtB costs for Skills" button
Click the "Set AtB costs for Special abilities" button
Set your skill level. If you're really new to Battletech, choose Ultra-Green or Green. Just trust me on this.
Check these options (remember, these are recommended settings to get you started. If you wish later to use different options for a different experience, feel free! The idea is to give you an options set that gets you up and running):
Under 'Unit Administration':
-Use the Share System
-Exclude large craft from unit value
-Customize retirement rolls
-Use leadership skill
-Use vehicles
-Clan OpFors use vehicles
-Display a report when contract market refreshes
-Display a report when unit market refreshes
-Uncheck "Do Retirement/Defection rolls at contract completion"
Under 'Contract Operations':
-Limit lance deployment by weight
-Limit lance deployment by size
-Use commander strategy
-leave base number of lances at 3
-leave rank per strategy at 1
At the top of the next column to your right, under the 'Scenarios' heading:
-Allow enemy VTOLs
-If you're going to employ vehicles yourself, check "Adjust lance weight for player vehicles"
-Random enemy capture
-Set delay timer to at least 1000
-Finally, UNCHECK double enemy vehicles
You can select whatever RATs you want, but I would recommend only putting in those that involve your unit's current years. You can always add more later once you reach the relevant years.
Repair and Acquisition tab:
I would turn off maintenance for now if this is your first time playing AtB. You have enough to juggle as it is.
However, if you insist on using it:
-Check Make maintenance checks
-30 days maintenance cycle length
-0 maintenance modifier
-Check Only damage parts that are already at "A" quality
Under 'Acquisition':
-1 day waiting period between rolls
-For now, set Acquisition Skill to Automatic Success so that you can instantly get your parts. You will change this to Administration later once you have acquired your initial parts stockpile.
-Check "Only support personnel can make acquisition checks"
+2 penalty for Clan equipment
0 penalty for Inner Sphere equipment
2 maximum acquisitions per day
Under the 'Delivery' heading:
2d6+0 days delivery time
1 day minimum transit time
1 day delivery time reduction per MoS (stand for Measure of Success)
Tech Limits tab:
-Check limit units and parts by year
-For years past the Clan invasion, check Allow purchasing of Clan units and parts
-Check Allow purchasing of Inner Sphere Units and Parts
-Check Only allow canon units for purchase. However, you will not be able to buy custom units you might create in this case.
-Maximum tech level Experimental
Personnel:
-Check Use Tactics Skill
-Check Use Toughness
-Check Allow Special Abilities
-Check Use Pilot Edge
-Check Use higher-precision skill averaging
Finances:
Leave these all unchecked until you have acquired your Mechs, Mechwarriors, and starting support personnel, EXCEPT for Limit loan parameters by unit rating.
I like to set the Clan price modifier to 4.0, but then I usually start in 3025 or earlier. In an era where Clan parts are more common, you can use something smaller to your judgment. There is no official AtB rule as far as I can find.
Mercenary tab:
Click the first radio button (the IntOps Beta option), and also check "Base on equipment sale value." Leave it at the default 5%.
Experience tab:
1 XP for each completed scenario
1 XP for every 1 kill
1 XP for every 25 successful tasks
1 XP for every 1 month on a 10+
2 XP awarded to the negotiator of a new contract
1 XP for each admin every week
Skills tab and Special Abilities tab:
These are already set for AtB rules as you clicked their buttons on the AtB tab earlier.
Skill Randomization, Rank System, and Name and Portrait Generation I leave at defaults.
Personnel Market tab:
Make sure this is set to AtB market
That takes care of the Campaign Options.
Now, go set your MegaMek options, to whatever you like to use for MM.
Click the GM Mode button at the top right of the MHQ screen.
All right. You are now ready to acquire your first 12 Mechwarriors and 12 support personnel (recommended breakdown is 10 Mech techs, 1 admin [probably Logistics], and 1 doctor). You may or may not get 12 Mechs to start with - it is possible for a Mechwarrior to start the campaign Dispossessed! If you want to generate random Mechs (or Dispossessed) for your initial unit, use the attached Excel file at the bottom of this post, in conjunction with the AtB Company Creation tab found in the rules file.
Go to the Marketplace menu option and select "Hire Personnel in bulk." Hire 12 Mechwarriors. MHQ will automatically generate them for you. Some of them will have special piloting advantages (SPAs), most likely any elites or veterans you get.
- Your first Mechwarrior is your unit commander, who gets a +1 to both piloting and gunnery skills, as well as 2 points distributed randomly between Strategy, Leadership, and Tactics - but you'll need to add those manually. I add these on top of whatever points the commander may have started with (most often you'll see some starting MWs with Tactics points already).
-your second, third, and fourth Mechwarriors are your other officers and gain +1 in either piloting or gunnery, whichever is lower. If they are equal, you choose. These Mechwarriors also get 1 point randomly in Strategy, Leadership, or Tactics. Again, you'll have to manually figure that out and apply it.
-Any Mechwarriors that are elite after the bonuses are applied get 2 SPAs, which are rolled on the table found in the AtB rules - Company creation tab. Veterans get 1 SPA. These can be on top of whatever natural SPAs those pilots may have rolled. Any Regulars or Greens that happened to generate SPAs can keep those, as well.
-Finally, when you edit your Mechwarriors, make sure all of your initial pilots get the 'Founding Member' check box marked. This gives them each an extra share and also makes them more likely to stick around at retirement time.
-Add your support personnel using the Marketplace menu as well.
-Add your Mechs. To actually add the Mechs you generated (however you did so) to your roster, go to Marketplace - Purchase Unit. Use Add (GM) to add the units to your roster immediately (using the Automatic Success means you would still have to wait for delivery).
-Assign your Mechwarriors to their Mechs by going to the Personnel tab, right-clicking on the MW, and choosing Assign to Unit.
Now you can assign your Mechs into lances.
To do this, go to the left-hand window of the TO&E tab and right-click on the unit name to bring up a pop-up menu. Left-click Add New Force, then type in the name of the lance. You can create more than one lance. For each lance, right click on its name, then left-click Add Unit to add a Mech to that lance. You may need to double-click on the unit name in order to expand the organizational tree so you can see the individual Mechs and Mechwarriors in their lances. Lances must have at least 3 and no more than 6 units. I highly recommend not placing all of your Mechs into lances from the start! Keep two or three unassigned to use as reserves in the event of a unit or warrior being lost or damaged and not easily repaired.
Go back to your Campaign Options - Finances tab and check everything except the last two options. Then, using the Add Funds (GM) button, give yourself a starting capital (I use 10% of total starting assets, which comes out to about 1.8-2.2 million Cbills.) Next, take out a loan. You likely won't make it to your first planet without taking out a loan for transport and/or maintenance costs. Ensure your Collateral slider is at 100% and that you are repaying on a Quarterly basis when you do this (standard AtB ruleset here). You will be limited as to just how much you can take out.
Next, use the money you just acquired to build a stockpile of parts, weapons, and ammo. You should be paying from your initial capital for these, but it's up to you whether you're also going to wait for transit times or just instantly have stuff show up, as this is supposed to represent your initial stockpile that you've already acquired (you can use GM mode to instantly deliver everything. Shift-click to select all.).
Once you have finished getting all your parts, go back to the Repair and Acquisition tab and set the Acquisition Skill to Administration.
Next, get a contract in the Contract Market. You always get two contracts to begin. You are NOT required to accept either of them if you don't want them, but you will have to then find a way to fund your unit until new contracts become available at the first of the next month! Also, these contracts may possibly be poor for a newly created unit to engage. If you want to really get a beginner's contract, try for Garrison Duty or a Cadre Duty contract (GM generate until you get one).
To shorten your travel time, pay attention to the number of jumps in your contracts! You can customize the distance for locations of your contract offers in Campaign Options - Against the Bot tab. The default is 800 light years; you can experiment with 500 or 250 or even lower. While this will potentially reduce the number of contract offers you see, it will greatly reduce transportation cost and the number of times you have to "Advance Day" to get to your contract location and your first MegaMek battles in your campaign.
Once you accept a contract, Go to the Interstellar Map tab and type in the name of your target planet for the contract. Don't Begin Transit just yet though, as there's one more step to complete.
You'll need to fill out your Tech and Doctor teams with assistants. Do this in Marketplace - Astech Pool - bring all Tech teams to full strength, and do the same for the Medic Pool.
Normally, this would be the point where you would want to assign a Tech to each Mech. If you are playing with maintenance, however, you can avoid having to deal with maintenance issues by mothballing your Mechs until you arrive at your destination planet. Travelling to your destination can take time, and if you didn't start with a veteran or elite tech, you could find your Mechs falling apart before you ever start your first contract! To mothball a unit, go to the Hangar tab and right-click on the desired Mech. Choose "Mothball unit" from the menu and select a Tech to perform it. Mothballing usually takes at most two days for any given tech and cannot fail. Know that it will unassign any Mechwarriors and techs assigned to that unit, as well as remove it from the TO&E (but you had to HAVE a TO&E to get a loan in the first place!).
Now go back to the Interstellar Map tab, and click on Calculate Jump Path. Then Begin Transit. Now sit back and keep clicking "Advance Day" until you reach your destination. Know that sometimes news bits pop up on a given day, so you might not want to click TOO quickly.
Once you're on planet, the first thing you should do is Activate all your mothballed units, reassign the Mechwarriors to them, assign techs to them, and then reassign your Mechs into their lances. Your contract will require you to deploy at least one and possibly two lances for some type of "standard duty" as dictated by the type of contract. You'll see this in the Briefing Room tab, in the lower-right corner of that window. Assign your lances so the requirements for each duty type are filled by at least one of your lances. After you do this, you can just click on Advance Day until a battle crops up. Have fun!