Anyone know where I can buy the books from?

There's normally a set or two going on ebay but it would probably be cheaper and easier to join a class (£9.95 before jan 25th) and you'll deffo be getting the most up to date set :) x
Pick up women's magazine on Tuesday. There is a free join voucher. It will only cost you 4.95 then for the full set and the talk about how the plan works! Xx
I agree with the above - you sometimes see books on e-bay but they're usually more expensive than just joining at a class. Plus by going along you'll get a good up-to-date explanation of the plans, and you might even enjoy it and decide to keep going (I didn't, but lots of people do). :D
I have always found some cheap ones at bootsales if you are on a budget