You don't need to buy books for the aptitude tests. These tests are designed to be made after a 5 minute explanation, and believe me... they are NOT that difficult. The stories of people that tell you the tests are extremely hard come from the people that made it through these tests and who like to believe (or make you believe) they made it because they are extremely good and talented.
Reading all these books just makes you extra nervous. Stick to studying the "introduction to" booklet. Apart from that look at the test examples on the website that is mentioned in the sticky interview thread, so you know what to expect. All I can say is... don't worry about these tests!!! If you have the talent to be an ATCO you will very easily pass the aptitude test.
Buying and reading all those books is a waste of money and a waste of time in my opinion!
