This is my personal experience – others may differ;
First get a “PritStick” and glue the first page of the BGB to the inside front cover. You are going to spend a lot of time turning to the contents page and that first page gets in the way (and costs you time in the exam).
Second, draw a series of horizontal lines with a fine pencil across the contents page so that you can easily see what page number any particular section is. I drew every third page number, which seemed to work well.
My personal opinion is that you need to be familiar with Parts 1,3,6 and 7. Read them until you know your way around them and understand what is in them – what they are referring to.
Scan through “Definitions” (Part 2) and the index so that you know what's in there and when it's worth looking in either of those (often a last resort to find that elusive reg).
Now LEARN Part 4 and 5. This is where to spend all your time. It's half the exam but it's all the useful stuff that you really need to know. Just bite the bullet and learn them.
As you know there are lots of books on the wiring regulations but none of them will help you to pass the exam. They are all written from the point of view of teaching you about domestic electrics in general. If that's what you want then say and I'll give you book recommendations but if you already have the necessary background knowledge then save your money because they wont help you pass the exam.
I have tried 3 different practice exam software discs. None of them are any good. It is helpful to be familiar with the look of the screen and the way the exam works but other than that they are, to a greater or lesser extent useless. Some of the questions are poorly worded and because none of the software training aids that I have tried have referred to the reg number in the solutions there is no feedback loop which increases your understanding of what reg is in what section of the book.
At the end of the day remember it's a test of looking regs up NOT remembering them. Learn what goes where in the book and read the question very carefully to see what part of the book to go to to find the answer.
Having said that the 2382 exam I sat on the red book was very carefully worded and unambiguous. It was tough but clear. I have recently sat the 2382-12 on the green book and it was a joke. Very badly worded and ambiguous.
I kid you not this is the exact wording of one of the questions;
Four of the tests listed in BS7671 are;
a, Earth fault loop impedence
b, continuity of ring final circuit conductors
c, Insulation resistance
d, continuity of protective conductors
How do they expect you to answer that?
Incidently you can find more of these questions in a thread I wrote which I think is called 2382.
Good Luck