AP Environmental Science
If you are planning on taking AP Environmental Science I don't have too much to say to you. The test is easy relative to many of the other AP tests that are offered, but don't just blow it off (completely). I do have a few words of advice though. If you are planning on taking AP Biology, AP Chemistry, and/or AP Physics, you should do that first or take them the same year. A lot of the material tested on Environmental Science overlaps with those tests, and it will make your life a whole lot easier if you already have some background knowledge. Even if you don't take any of those AP sciences, you should have a general background knowledge of all of them or you will find yourself learning a lot of new material.
As far as books go, I used the Princeton Review AP Environmental Science review book. I only have one complaint that they were a little bit too casual at times, but otherwise it was very helpful and helped fill in all the holes and all the information I had not yet learned. I also used the REA AP Environmental Science Crash Course book which I read the night before the test.
All in all, I probably spent about 5-10 hours on studying for Environmental Science. I started reading the book about one or two weeks before the AP test.
Also, on the test, use your common sense. There are always a lot of questions that you can get by just using your common sense and reading through the question carefully.
Otherwise, I didn't really do much other preparation besides get a decent nights sleep the night before. I don't think you should worry too much about it; you should be able to do relatively well without as much effort as many of the other tests (not that I'm saying you shouldn't study...)
Again, feel free to comment if you have any questions what so ever at all!