Easy guide to truss rod adjustment.
Fret your G string at the first fret with your left hand (if it's a righty), fret the last fret with your right pinkie and also reach over to the tenth with your right index finger. What your aiming for is to have a bit of relief at the tenth, which means that with the first and last frets fretted, the tenth shouldn't be either high off the board or touching the fret, it should be just off the fret a little. Guesstimate roughly how much your fretboard needs to come up or down (if at all) and then move onto the next step.
If it's to high at the tenth, turn the truss rod to the left, you don't wanna crank it, short turns, a quarter turn MAX if it's well out. Look down the fretboard as you do it, you'll see and hear the fretboard move, then restring, tune to pitch, wait an hour and adjust again if needed. You may need to adjust it a few times since you have to take the neck off, on a strat it's easy peasy and you can get it first time nearly all the time.
