Molly DiBianca listed her top 30 writing blogs and I have been commenting on her picks. The writing blogs I keep reading:
Confident Writing is from Joanna Young, a writing coach, who organizes theme months and participates widely in blogger-world events. This is a very busy blog.
Copyblogger is Brian Clark who covers online writing and effective blogging.
Manage Your Writing, is from Dr. Ken Davis, and it is one of my favorites for its short and crisp tips.
Writing, Clear and Simple from Roy Jacobsen is very readable even though he also addresses legal writing issues.
Writing Tools by Poynter Online from The Poynter Institute is an authoritative resource.
Bad Language from U.K. blogger Matthew Stibbe discusses business, technology, and marketing using effective writing.