The New York Times has an article today about authors who blog. They were all very interesting and one thing is for sure. Authors use their blogs as uniquely as they write their books. Some were diaries, some shared book ideas, some shared book characters. The book part of the blog seemed to work best for nonfiction topics where the author was posting ideas or facts and getting feedback, ideas, and pointers to sources.
The New York Times > Technology > Dear Blog: Today I Worked on My Book.