I found Air Law to be the hardest of the PPL exams as it's mostly a memory test, but here's a little trick to make it a bit easier :
When reading the whichever book you are using, stop and think and visualise a situation when the bit you are reading would be needed. For example, which side do you overtake on in the air? Answer : on the right. So imagine, really imagine yourself in your C150/PA28/whatever, coming up on a slow flying Cub. Really try and imagine yourself coming up behind them and moving right to overtake. Look out of your left window and wave. In the Cub you can see John Farley (or someone else very recognisable) who waves back. Now you'll always remember which side you overtake a slower-moving aircraft on.
Yes, it takes a bit of mental effort to do this sort of thing, but it makes learning air law a bit more fun and you'll remember more of it.
I first heard about this "silly visualising" technique at a live performance given by Dominic O'Brien, current world memory champion.
Confused
by QNH and QFE? Well, they don't actually stand for anything, so invent something. In my case, QNH = Naval Height (i.e. asl), QFE = freekin' eerfield (best said with a Scouse accent).
Even air law can be fun!
Mik