A massive gallery site showing off tons of Amateur Astronomer's images. See images from the best Astrophotographers around, or beginners like myself. A fantastic resource for checking out what you can achieve with various equipment setups.
What do you do when it's cloudy outside? Visit Cloudy Nights to talk about the hobby, and learn from others. I have learned more here than any book or tutorial can teach. The forums are a great community resource, where all kinds of individuals provide very helpful information regarding this hobby and the many topics within it such as scope selection, mount selection, camera or imaging issues. There's also a great classifieds section to pick up well loved equipment.
Starizona's Resource Section
Starizona makes and sells all kinds of unique gear for the astrophotographer, but they have spent time keeping an excellent resource section that covers the basics of telescopes, imaging, and includes videos, a glossary, and tons of tutorials.
This website provides a bunch of useful tools including an FOV calculator so you can see what night sky objects look like using your telescope, eyepieces, or camera equipment. There are also calculators for CCD Suitability, Focal Length/Ratio, Magnification, and Telescope capabilities. It's a great resource!