I'm only 16, but I'll be able to vote for 2012 election. What should I know before voting?

I will turn 18 in October next year. Presumably, I will be able to vote for president. I don't want to be one of the people who watches a few tv interviews a few weeks prior and then just votes; I want to be fully educated on the candidates and their standings. What should I do to better my knowledge so that I can make a good choice!? I want to start now. I watch the nightly news and keep up on the basic news.