A beginner's questions regarding Alpha Strike

[Scorpion]

I am just starting out with Battletech (and tabletop games in general). I recently bought the introductory box set, read through the Quick Start rules, and played the green training scenario.
   Now, I’m pretty sure I want to play with the Alpha Strike rules (mostly because I want to eventually play with a large number of units) and my question is, should I read through the Introductory rule book and play through the training scenarios and such, or should I just skip right ahead into Alpha Strike? Also, does Alpha strike contain scenarios for beginners similar to the Introductory Rulebook? If not, can I use the scenarios in the IR to start out with Alpha Strike? And, as a less important question, are the other books such as Total Warfare, Tactical Ops, Strategic Ops etc. useful when playing Alpha Strike?
   Any Help would be greatly appreciated, thank you.

[nckestrel]

The rulesets have some similiarities, but I don't think playing through the Intro Box Set scenarios/rules is really that helpful toward learning Alpha Strike.  The introductory box set rulebook was the model for the Alpha Strike basic rules, so anything that carries over rules-wise is already in the Alpha Strike rulebook.
With the Alpha Strike Companion, most everything useful to Alpha Strike from TacOps, Strategic Ops or Total Warfare are either in the Alpha Strike rulebook or Companion.  Tech Manual would be useful if you want to construct your own units or variants of existing units (and TacOps has more construction rules).  The rules for converting the units to Alpha Strike are in the Alpha Strike Companion, but the building units rules would be a complete copy of Tech Manual anyway..
The Alpha Strike rulebook has some general scenario types (and a generic campaign) and sample companies.  I would suggest picking one sample company for each side, a scenario type, and having fun.  Then moving on to the campaign. Later on, I'd suggest Total Chaos or any of the Turning Point PDFs for more scenarios, including campaigns.

[Von Ether]

To get the latest updates to the core Alpha Strike rules, you should include the errata: http://d15yciz5bluc83.cloudfront.net/wp-content/uploads/2014/08/Alpha-Strike-v2.0-2014-08-27.pdf?28cf69

And you should use this thread: http://bg.battletech.com/forums/alpha-strike-101/the-place-to-start-alpha-strike-ibs-battlemech-mul-links-collected!/ to download all of the Alpha Strike cards for the mechs in the intro box. (Thanks again to iamafanboy collecting them in one  thread and thanks again to the volunteer MUL team for getting them there in the first place.)

For your immediate concern, this changes the PV values of the sample companies. Long term, you'll find that the changes keep Size 1 and 2 mechs competitive, but stops them from camping in the woods and sniping all day.

There's no training scenarios, but I suppose you could borrow the ones from the Intro Box with the caveat that you just using them as a excuse to push some plastic around on table to get a feel for the game. If you feel real nervous, start with the Basic Rules and work into the Standard Rules.

If you keep only to mechs, then there won't be much new in the Standard rules except for more cool Special Abilities.

That's where AS live, in the Specials and Special Abilities. If you ignore those starting out, you game will be very vanilla, so don't judge it until you start using them.

To add even more spice to your mechs, get the Alpha Strike Companion when you can.