I passed the first three a couple of weeks ago. Air law, HPL and procedural ops. Only used the Pooleys books,read them over twice on my commute then got the Mrs to test me, she's a teacher so really enjoyed pointing out where I was going wrong! (In air law and in life!) There is a London based ground school run by aopa twice a week in the evenings if you're that way , I struggled getting hold of the chap though and self study seemed to work fine for me so giving that a go first off for the principles of flight and the general knowledge round .
My day job is legal and I found you have to suspend that part of your brain for the exams a bit. There's a couple of Qs where interpreting things too carefully might lead to the wrong answer.. there are flaws, but not so many that will jeopardise your result if you know your stuff.
Anyway, old hat to most on here I'm sure. Good luck!