well for one thing you got onto studentdoctor so there's a good start haha. spend every moment of not studying on this forum and it'll prove very helpful in the long run. now as for how to get started, kaplan is a good starting point. Have you taken a diagnostic yet? and if so, which areas are you weak in. Regardless, knowing the material in the kaplan text book is first step. I went through that book from cover to cover about 3 times before I felt comfortable with the material. Don't expect to know everything after reading it once. Repetition is key. If you don't understand something from the book, pull up wikipedia or your bio/chem/ochem textbooks from class and get a better understanding. Hopefully you still have those lying around. Worst case scenario, if you still don't understand, just search the forums to see if the question has already been asked. otherwise just make a post, most of us here are glad to help a fellow pre-dent student.
Once you feel you have a thorough understanding of the information in the kaplan book. I suggest moving onto DAT Destroyer. Don't use it as a means of testing whether or not you know your material. When I went through it first time, I was shocked to only be able to answer about 80-90 out of 300 Bio questions. Use it as another study aid and go through question by question and make sure you fully understand the question, the answer as well as the wrong answer choices and why they were wrong. That's the only way to get a complete understanding. All this takes lots of time. Im sure you're aware but it's no walk in the park. Takes time and dedication but i'm sure you'll pull through =)
DAT Destroyer itself took me quite some time to get through. Once you're done with that. Take a practice exam from either DAT Achiever or Topscore to see still where your weaknesses are. After taking the exam, do the same thing you did with destroyer. Go through all the questions and all the answers.
Now besides the sciences, if you need help with the PAT, there's Crack Dat Pat. I doubt you'll need anything more than the ace edition. Just google it. It's actually a bit tougher than the actual PAT, so if you can get through that, you should have no trouble with the actual PAT section.
Reading Comprehension section is also a pretty important section. There's no real study aid for this section. Just read a lot of science journals to get an idea of the type of passages you might find on the actual exam. Part of the difficulty of the RC section is being able to read 3 passages as well as answering the 15-17 questions for each of those passages in the allotted time. So reading quickly and efficiently is key.
Quantitative Reasoning is..well just math. From what I hear from most schools, it's the least looked at score on the exam but obviously you can't bomb it so just work on remembering those formulas. The questions are similar to SAT math questions so if you wanna prepare, just buy a cheap sat book and do the practice problems from there.
Finally, you have lots of time before your exam but don't procrastinate. The key to doing well in this exam...and well anything in life for that matter is repetition. The only way to be comfortable when you go take your exam in June is go over the material over and over again. Don't slack off! Good luck =)
EDIT: Oh yea, lay off the caps. It doesn't help to read something when it feels like you're yelling at us haha.