As discussed elsewhere, the best way to prepare for the Theory test (both the multiple choice and the hazard perception sections) is to do so along with practical on road driver training.
Click here to go to information on CIA's structured 1stPass Training Course
You should also click here and read What is Driving?
However, there are specific things you can do in addition to this:
For the multiple choice part of the test, there are a number of publications that we recommend you study:
Or you can go to our Free Online Theory Tests.
For the Hazard Perception part of the test, we recommend the following: