One of my favorite sites on the web is Monergism.com. It is an outstanding resource for study and devotion. Monergism has a wealth of theological resources ranging from articles, audio, a bookstore, a blog, and more. Check out their bookstore for great prices on great books. Also, if you have any teaching responsibilities in your church you will find a vast number of resources to enrich your study. If you simply have questions about the Bible or a theological issue then Monergism will prove to be very helpful to your search.
Monergism is in the process of updating their site. Great looking design!