I have the answers that you seek!
My son is now in 10th grade, and so far will be finishing up with 6 AP exams, including US History, US government, Chemistry, English Language, Calculus AB, and Biology so far. Average score is 5 so far.
It is easy to do.
Purchase the Barrons study guides (they are the best guides, IMHO) for all of your classes.
Go to PAHomeschoolers.com and sign up now for as many AP classes as they have online. We did 2 classes with them, and it was lots of fun to have such a great online community and feedback from a teacher. IF they don't have your area, there are online sources for AP classes. Some of them are free, check out hippocampus and also MIT open coursewear for some examples. Some online classes cost money, I would not pay more than 350 per year for an online course.
Start studying, and go onto the collegeboard website. Download each and every one of their "old exams" when they have files with the free response questions and detailed answers. Do the old tests over, and over again until they are second nature. Do each and every question in the Barrons books. You will do fine.
Also, google "AP (insert class name here)" and you will often find teachers websites with their entire syllabus right on there for free, maybe even with downloadable worksheets!!!!!!!!!!!