WhyIslam is a great place to start. It covers pretty much all the basics of Islam and addresses many frequently asked questions. They also have a nice forum where you can interact with others and ask questions.
Quran.com is one of my favorite websites. It has the entire Quran (which Muslims believe is the literal word of God) in Arabic, English and many other languages. Remember that the Quran only truly exists in Arabic, since that is the language it was originally revealed in. All translations are considered "interpretations of the meaning of the Quran," because translations require human input and can never be perfect.
How Muslims Pray:Have you ever seen a Muslim pray? Have you wondered how its done? Well here are a few nice resources for that. First is from a blog, Slice of Lemon. It's a simple explanation of how to pray, presented in an entertaining way and is nicely organized. This video is a really well make guide on how to pray, which gives you some good background information as well. Here's another well organized Salah Guide with great pictures.
If there's anything else you think should be added to this list, please let me know here