I’ve often been told that I’m a good writer.  Personally, I think I’m probably slightly above average, but I’m no Hemingway.  I found a great resource on improving your writing over at Copyblogger.  Their “Copywriting 101” series provides a series of articles, each of which can be read in a few minutes, that should help you write better than you do now.  If you’re serious about blogging, I recommend checking it out.