There is so much advice out there that one must sought the wheat from the chaff and that is very hard and time consuming. There are some good writing blogs around by some hard working authors. I would say choose a half-dozen or so who themselves get good feedback from their posts. Concentrate on these people and see what the common denominator is on a particular subject, see how they market their own books, gather up their thoughts on writing. Some of these bloggers can be very inspirational.