Someone PMed me for advice, and this was my response:
If you've just finished up gen-chem and o-chem, it will all be fresh in your mind, which is perfect. I would also think your background will give you an advantage on the PAT and QR sections: your CAD and drafting classes will have prepared you for a lot of what the PAT is, and no matter what you've done you will have more experience dealing with mathematical problems than most of our pre-dent classmates.
As for a study schedule, here's what I did May-July (in a similar situation as you, taking summer courses): Morning classes, afternoon study outside at school or in the library. I was usually home by 4-5 to eat dinner with my family and go to the YMCA and stuff. Maybe twice a week I'd go back to the library to study until 9-10. I think it's good to have a fairly regular schedule and to study at school to avoid distractions.
What I studied: well, lots of o-chem because I was taking those courses! For this, I just used a text book, the study guide book that accompanied it (explained answers, etc), lots of flashcards, and internet resources to help explain things in a different way. Gen-chem I just used my old text book and the internet again. Biology is used Campbell's "Biology" text: it is very thorough, covering all basic bio as well as any physiology or anatomy that might show up on the DAT (technically should have been cover in pre-req. bio courses).
When I worked out of text books, I not only read and re-read the material, I also did as many practice problems as I could stand. None of the super-challenging ones, just the basic questions you might be assigned in a class. This helped a lot, I think, especially for the bio section. Don't get too caught up in calculation-type problems for Gen-chem: this section focused more on concepts, with any calculation problem being simple as long as you knew the concept. Don't skip formulas, though! Really now why they are what they are. O-chem was straight-up flashcards along with some internet pratice for NMR & IR stuff.
I didn't do much else for my PAT study than take practice tests. I had the one on the ADA website, the 3 Topscore test, and a couple from a few different editions of the Kaplan book. The key was to do each test multiple times like it was a real test, then go back and study what I got wrong. And, each time I took the test, I forced myself to rationalize why I was choosing that answer (even though I had memorized it after about the 3rd time or so).
Actually, I used this practice test method for all of the sections. I was constantly taking section tests (usually PAT or the whole science section), studying the concepts and problems I missed, then retaking the tests. Before I would start re-using and studying a test, though, I would take the full-length practice test. This means I took about 4-5 full-length practice tests before I took the actually DAT. Don't get too hung up on those scores; just realize how you are taking the test, as your test-taking skills (time management, efficient reading, etc.) are a big part of taking this thing.
Anyway, I gave the QR and RC sections the least attention and don't really have many tips here. I think if you approach QR like o-chem kind of you should be good. There seem to be a set number of "problem types," if you memorize the way to solve these problem types you should be prepared for whatever permutation of that problem they can throw at you. You can probably just use the internet to study this stuff along with your practice tests. I don't think Kaplan or the above mentioned practice tests are enough, though. Use the internet.
RC is what it is: just don't blow it off because English is your 1st language. Maybe some LSAT books might be good to use...
Well, I hope this helps some. I might actually repost this email on the forum so others can read it. Good luck!
