Fret the g at the first fret with your left hand, then with your right, fret it at the last fret, now stretch over with your index finger of your right hand, and see how much relief there is by fretting the tenth or eleventh. You want a bit of relief there, not dead straight, so if the neck needs more relief, as in, it needs to move away from the string, loosen the truss rod by turning it to the left, if it needs to go up, turn it to the right.
You don't need to turn it that far, watch the middle of the fretboard while you turn it, you only need a very maximum of an eighth of a turn (that's half a quarter), and i'd say that's in an extreme case. When you do, leave it for a couple of hours to let the neck reform to it's new position and settle down, then check it and maybe you'll need to readjust.
It's alot tougher to get right first time with a rod where the adjuster is located in the neck heal because you have to judge it by eye, loosen the strings, remove the neck then adjust and see how it is. On a strat you adjust the truss rod with the strings on.
