This is a reprise of a popular blog post published some years ago.
The EFF has released a Legal Guide for Bloggers. Included in this guide are sections on defamation, reporter's privilege, public records, and workplace blogging. But, the best section, in my mind, was Bloggers' FAQ: Intellectual Property. This section covers copying of other blogs, government documents, Creative Commons, licensing of comments, deep linking, copying of images, the DMCA, trademarks, and right of publicity. If you have any questions about intellectual property and blogging, check it out.