I use a combination of Kaplan AAT Units 1,2 & 3 and Osborne Business - Business Accounts by David Cox. Osborne also do revision units online -http://www.osbornebooks.co.uk/home - which I find useful too. I hope this helps.
For the manual levels 1,2 & 3, I used "Book-keeping and Accounts" 6th edition (I believe it is now 7th edition) by Frank Wood & Sheila Robinson (ISBN 0-272-68548-1)
It was my bible, and is still my reference when I need a refresh.
For the computerised levels, you will need to understand you software, particularly the reporting functions. I used Sage for my assignments. The help section and the online help (AskSage) were a good source of information. I also used "Computer Accounting" by Micheal Fardon (Osbourne Books isbn 1-872962-27-0) which covers computer accounting and uses Sage examples. Obviously if you are going to use different software, then you need guides for that
HTH Bill
-- Edited by Wella on Wednesday 23rd of March 2011 12:54:51 PM