SourceForge (Probably the largest collection of open source software available on the web.)
Forge.Novell.Com (Nice free cvs project hosting service similar to sourceforge.)
The Cathedral and the Bazaar (Possibly the most famous writings on the open source movement and Hackerdom by Eric Raymond.)
CVS Clients (A collection of CVS clients, which you can use for getting hold of and contributing to all that free software.)
The Home of CVS (aka cvshome.org, the producers of the *nix cvs repository system used the world over. Includes the definitive online documentation for using a cvs repository)
Tortoise CVS (Tortoise is without doubt the greatest windows cvs client. Making cvs commands part of the explorer shell is a master stroke.)
What is CVS (If anyone ever asks you, direct them to this link. Its the rtfm of all things cvs.)
Software Freedom Day (Software freedom day is an organisation which promotes the use of open source software. They engage in real world activities including seminars and distribution of free CDs.)
Open Source Licence Law Resource Center (Very useful site for those working with Open Source programs and code looking for information about legal issues relating to their projects.)
Free as in Freedom Free as in Freedom is Richard Stallman's biography by Sam Williams. Richard Stallman is the founder of GNU and the Free Software Movement.
If you have any useful generic links to all things open source, please submit them via the Feedback link.