Windows sans mouse
Windows sans mouse is a project to help Windows users learn to use their keyboard more and their mouse less. Why would you want to do that? To save time. There's nothing wrong with using a mouse, and sometimes it's absolutely essential. But it's often faster to do without it. See more discussion here.
I've made a Twitter account @SansMouse with daily tips. You might want to get into the habit of relying more on the keyboard by practicing one tip per day. I also have a personal Twitter account @JohnDCook.

If you use an RSS reader such as Google Reader but don't use Twitter, you can subscribe to the SansMouse RSS feed.
If you are interested in a site for Macintosh keyboard shortcuts, see @commandtab .
I have five other Twitter tip accounts: @RegexTip for regular expressions, and math accounts @ProbFact, @AnalysisFact, @TopologyFact, and @AlgebraFact.
Related links:
Grouping basic keyboard shortcuts into patterns
Keyboard shortcuts for Microsoft's most popular software
Keyboard shortcuts for Firefox