Blogs and web sites are good starting points, but you cannot stop there. Yes, you have to have a web site when you have a book. Yes, you have to have a blog when you are getting ready to have a book. Once you have the book, you need to look at different ways of getting the message out.
Ah, I hear the cries of "This is way too much work." It is a lot of work, but if you want to be successful as a writer, you need to consider every possible angle. More and more of the big publishing houses are limiting the amount of marketing they will do for a new writer. Maybe 6 weeks of hype, then you are on your own.
Might as well practice now while there is still time.