At risk of sounding like Oprah, I wanted to list a few of my favorite things that I go to for more head knowledge as an atheist, and student of science.
1) The A-Unicornist site- This guy has to be the greatest kept secret on the net. Why he isn't more recognized for his blogs is beyond me because they are probably better than just about any blog I've read, and I read a lot of blogs. He is also the one who played a major part in my own de-conversion, and I've known him since 6th grade; We've only recently got reacquainted through Facebook.
2) Atheist Experience Podcast- If you own an iphone or anything similar, you have got to download the podcast. I usually listen to the sunday afternoon show on mondays. They have several different hosts and all of them have great insight and knowledge. Matt Dillahunty is the founder.
3) The Universe series brought to us by the History Channel via Netflix-I've been watching the four year series on The Universe via Netflix and, besides noticing just how ignorant I am, have learned a great deal more about this awesome universe we live in.
4) Skeptic Magazine and The Skeptical Inquirer- I have a subscription to The Skeptical Inquirer and just swing by my local bookstore to purchase the Skeptic magazine that comes out quarterly. The publisher of Skeptic is Michael Shermer.
5) The Local Library- It's great to be able to request a book online and have it transferred to the nearest library for free, nuff said.
6) Dead-Logic.com, John Loftus' blog and any other blogs that I follow are also great resources.
7) As far as Youtube goes, I like to listen to everybody's favorite transexual Zinnia Jones, the always insightful AronRa, the hilarious nonstamp collector, Thunderfoot and the incomparable Edward Current.