If you have made your purchase(s) at the time of first registration of your details, when you login from the homepage, you should now see a welcome screen enabling you to select your choice of subject to use. 

Select your subject and submit.

If you have registered but need to make a purchase, login on the bottom left of the 'register and buy' screen, make your purchase(s), then login from the homepage to use immediately.  You will be able to make your purchase from 3 months before the examination date.  Typically CIMA products will be available from February for the May sittings and August for the November sittings.  ACCA products will be available from March for the June sittings and September for the December sittings.