After Knock, Knock, Seth Godin's last e-book, it's only natural that he follow up with Who's There (free for now). In the new book he takes a look at blogging. Not a standard how-to, but:
"Instead, I divide the blog world into three groups and turn my attention to one. And in particular, I try to sell you hard on how building a blog asset can have a spectacular impact on you, your career, your organization and your ideas."