Robert Scoble and Shel Israel have posted chapter four online of their book on business blogging. There are some valuable lessons in there:
"Blogs...have already proven to be the most powerful tool to directly access company constituencies, short of buying your own printing press. Come to think of it, blogs are a whole lot less expensive than a printing press as well."
(Doesn't 'Robert Scoble' look weird without the underline?)