"A Legal Issues Primer for Open Source and Free Software Projects"

The Software Freedom Law Center (SFLC) has published a great paper called "A Legal Issues Primer for Open Source and Free Software Projects". It has straightforward explanations of Copyrights, Licensing, Patents, Trademarks, and Incorporation, and discusses how Free / Open Source Software projects should approach each one of these issues. This is essential reading for anyone involved in Open Source.