Yes, for the tax written papers you'll need the Tax legislation, which are the permitted books to take into ATT/CTA exams . Once you're enrolled, on your MyKaplan account there is a section labelled 'Legislation' where you will find discount order forms for the legislation you will need.
For the Accounting, Ethics and Law Computer-Based Exams you will need to purchase study manuals from the ATT or CIOT shop.