wheelercm,
if i were you i would also take a good, long look at the manual of the aircraft you have flown. knowing the aircraft you fly is always a good thing from the perspective of a pilot!
as for books, well...
aptitude test - i didnt prepare for this one at all, i believe that most people innately possess the things they are looking for (eye-hand coordination, logic). but if you really want something to look at, take a look at the sample Qantas psychometric test. this test has been mentioned numerous times in the forum, have a look for it.
personality test - there is no book for this, just answer truthfully. they will ask you pretty random questions about yourself, so you cannot really prepare.
mathematics test - the test isn't hard in terms of its mathematical depth, but it is very tedious and long winded. i suggest you practice your manual calculation skills, since calculators are not allowed in the test. i used the GMAT textbook to prepare for this test. the contents of the GMAT test are not similar to the CX math test in any way, but the main point is the GMAT practice tests will get your mind back into gear. have a try.
good luck!