Lately, a young MBA student called Caroline Himmelman started a blog aimed at helping artists with the business side of freelancing. Her writings can be found at candestine.com under the name The Art of Business. There is much in her blog that is seldom breached when talking about business, like balance sheets and health coverage. I can only hope that she keeps going!
Edit: little update to give the new URL http://www.artofbusinessblog.com/