Originally Answered: AP English Language and Composition?
It's great that you're eager to prepare for AP Language this early - being motivated is the key to success. Today, I just got my results by phone, and I passed with a 5. Here's my advice:
In AP Language, you study pieces of nonfiction and analyze them for rhetorical tools such as organization, diction, syntax, the appeals (pathos, logos, and ethos), tone, anaphora, audience, purpose, synecdoche, concrete vs. abstract detail, connotation vs. denotation, and argument techniques. You read pieces critically and carefully, annotating as you proceed so that you can either (1) answer multiple choice questions, or (2) write response essays.
The exam consists of two portions: an hour-long multiple choice part (45% of your grade) and three 40-minute essays (55% of your grade). You will have one or two rhetorical analysis essays, one synthesis essay (essentially a miniature research paper; you are provided succinct sources and must compile an opinion), and perhaps one argumentative essay. Class time is spent preparing how to write quickly and effectively while learning to identify and analyze rhetorical devices. A large emphasis is placed on becoming a global thinker - looking beyond the scope of your personal life by becoming better informed as to the world around you. You will go into the AP exam with outside knowledge that will enable you to develop structured and educated responses to the essay prompts provided. The concept of ANSWERING THE PROMPT (what my teacher told me AP supposedly stands for... :-) ) will be emphasized, and you will need to critically ponder questions in relatively sparse amounts of time. AP readers love essays that stand firmly near a position, use logic and examples to solidify points, and answer the questions "so what?" and "why?" Essays are not supposed to be in the 5-paragraph style with a 3-point thesis; they are to be less elementary.
You can prepare by purchasing an AP Language prep book and beginning to memorize the rhetorical terms listed in the glossary. While reading novels is always good, it will not be quite as beneficial for AP Language as it would be for AP Literature. I would suggest delving into some modern satire or perhaps reading distinctly unique excerpts from fiction. Famous historical documents and speeches are always beneficial ("I Have a Dream," "We Will Fight," "The Gettysburg Address," etc.). When reading these, try to put yourself in the writer's shoes. What makes them effective? What are the audience and purpose? How is credibility established? If you practice these things, you will be far ahead of your classmates when the school year starts!
I wish you the best of luck in AP Language! :-)