Lots! Quite a few of them are the blogs of other writers.
I've spent a lot of time on Lee Thompson's blog recently, working my way through all of his posts with advice for other writers. There are lots of tips in there about the craft of writing and I've enjoyed every post. I also read my friends Bec Zugor and Shaun Horton's blogs. I can often identify with the situations my fellow writers find themselves in!
Then there are blogs which are less about the craft of writing, and more about the marketing and business of getting published. The Bestseller Labs often have good articles on promoting your work sensibly and without annoying potential customers. Query Shark covers the basics of submitting a pitch for your novel: I talked about how useful the site is about a year ago. And the Smashwords blog often has interesting details about the market for e-books.
The Writers' Village blog covers both craft and promotion, so straddles the two areas.
That's not everything I follow but some of the ones I make the most effort to keep up with. Outside of writing I also read the excellent PC gaming website Rock, Paper Shotgun most days, and read my yoga teacher's blog.