If you want to test the waters before picking up the core books, or just want an easy way to create a character along with an adventure book, pick up this:
http://www.amazon.com/Dungeons-Dragons-Fantasy-Roleplaying-Game/dp/0786956291/ref=sr_1_2?ie=UTF8&qid=1296008660&sr=8-2It has a really easy step by step character creation thingy, and 2 basic rule books.
Normally, I'd just say go get the core books and skip this, since the core books have all the information that the above set has(with the exception of character creation) but it will teach you the rules in a very easy to understand way, plus you get a map and tokens in it.
I'll post my character sheet once I scan it. Also, I have a different character sheet format than what is on the wizards site, so don't be all like "wait wut" when you see it.