If you haven't looked at the blog list on my sidebar, I suggest you read Anne R. Allen's post today.
Her advice on selling books is the best I've seen lately. She separates the fiction from the nonfiction tips and there is a reason to do so.
Anne says that slow-blogging for fiction writers, once a week, is fine, but she believes writers of nonfiction should post twice a week.
After you read her blog, come back and let me know what you think is the best way to sell books in today's world.