Little gravity - but there's still some there. Sol's jump zone starts around 10 AU out IIRC, and Saturn orbits the sun at 9.5 AU. So you'd have roughly the sun's pull on Saturn to cancel out. Like Daryk says, that's why ships have station-keeping drives, which are there to thrust away from the sun and stay in the jump zone.
At 10 AU from Sol, the Sun's gravity is only 6.5 * 10^-6 Gs.
The current value for station keeping thrust is 1*10^-1 Gs, or about fifteen thousand times higher than the sun's gravity at the Z/N points.
Let's run some numbers. We have acceleration, I'm going to assume 180 hours, how far will a vessel at a Jump Point drift during that time if it wasn't using Station-Keeping Thrust.
D = .5 * A * t^2
A = 6.5 * 10^-6 Gs = 0.000063765 m/s^2
t = 180 hrs = 10,800 minutes = 648,000 seconds
D = .5 * 0.000063765 m/s^2 * (648,000 seconds)^2
D = 0.0000318825 m/s^2 * (648)^2 * (1,000)^2 * (seconds)^2
D = 0.0000318825 m * (648)^2 * (1,000)^2
D = 0.0318825 m * (648)^2 * (1,000)
D = 0.0318825 * (648)^2 * (1,000) meters
D = 13387.58928 * (1,000) meters
D = 13387.58928 kilometers
So a vessel will fall about 13,500 km if it leaves its station-keeping drive off. That is 750 Space hexes, but how does it measure strategically?
1 light-second is about 300,000 kilometers, so over a week the vessel will 'fall' .045 light-seconds, or 4.5% of a light-second. Even if I assume the gravity quadruples then that only changes the craft to falling 18% of a light-second.
Since 10 AU is 80 light-minutes, that fraction of a light-second is not a significant worry.
So Station-Keeping thrust is not needed for a Jumpship to remain near a Jump point, just thrust within the limit and back out again.