The tag Author is a popular tag often used by bloggers discussing the people who write and create books. Many authors also blog regularly and their blogs have huge followings. Some examples include the blogs of Meg Cabot, author of The Princess Diaries, and Malcolm Gladwell, author of The Tipping Point. Anastasia Suen has a nice listing of children's book author blogs on her web site.
More and more often, book publishing companies are relying less often on traditional book tours, and the burden is increasingly placed on the author to use their own blogs as a key means of promoting their books. In addition to using their blog to promote their own work, many authors are using their blogs to promote the work of other authors. A great example of this is Cynsations by the author Cynthia Leitich Smith.