This is what I used/recommend
1. Start out with Kaplan's book just for a very basic idea of how you should approach the different sections.
2. Read Barron's PAT section for more advanced tips (but dont buy it, thats a waste, just sit down with it at Barnes and Nobles for an hour
3. Practice every test in sight : Kaplan's tests on the CD, Acheiver, and Topscore.
4. Make note of every question you got wrong, try to understand why you missed it, and see what sections you need help on the most.
5. ALWAYS practice with a timer so you learn to never stick on any one section too long.
For me, on the real dat, i think angle rankings is the hardest, the 3-d box put together was the most time consuming (and difficult to master), and the cube counting the most frustrating.
for angle ranking, try putting your finger over the legs of the angles to get a better idea of the angle's size
I got a 24 on the PAT of the real deal, and I was getting 24's and 25's on the kaplan cd tests, but i dont remember my achiever or topscore scores
Hope that helps