One thing I've noticed everyone saying about AP style is that it significantly improves your chances of getting your information printed. It's easier to copy verbatim, or it's more articulate and easier to re-write for those journalists who won't just copy word-for-word. If a news release is printed in very casual writing, a journalist might not even take you seriously. AP style is the industry standard, and thus releases written in AP style are the most professional way. Now, not only will the reporter actually look at the information, but they are more inclined to use it in their writing.
An article I think describes the importance of AP Style best is "The AP Style Stickler" by Sandra Young.
So grab yourself an AP Stylebook online or your local bookstore (they're pretty cheap). Otherwise, check out the iPod app. Unfortunately Android market doesn't have one yet.
Want to learn more about AP style in general? Visit this short post about the basics.