Bernie Warren identified Kathy Schrock’s Guide to Everything site in his TPC discussion. It is a comprehensive site with tremendous information in a wide variety of topics. As far as screencasting goes, there’s something on it to meet the needs of everyone from beginner to expert. Check out Kathy Schrock’s site here.
Another less daunting way for those considering how to get started is to read The+Professor’s+Guide+to+Creating+Video+with+a+PC. This quick and dirty guide discusses equipment, software and post-production techniques that will serve your needs well. The guide was created by MediaCore, a company that for better or worse, no longer serves education institutions because it was purchased by a large media company and was repurposed for its own needs. None-the-less, the information remains valid.