This is the first hurdle; the theory test in the majority of cases pupils don't start this early enough, then it's a mad rush to get it done so we can book the practical test.
As previously mentioned in the theory test section there is good material that can be purchased from supermarkets or book stores.
Alternatively you can use the DSA website for training, if you want to give it a go click on the link below:-
http://www.theory-tests.co.uk/register 
This is free once you have registered, well worth a look.
Or if your into your DS Lite, they do a program.
Or better still if you have an iPhone they have a relatively inexpensive app you can buy.
Good luck which ever method you use.