We finally started our own blog after preaching about them for a year now. A blog is a great tool for any company to help get their product or company noticed. The blog just needs to be informative and needs to be goal driven. The main goal of a blog can be what ever you would like it to be. The main goal of our blog is to discuss what the company is up to and also talk about social media and its importance within your company.
Your blog entries don't have to be a 10 page paper. Your entries should get to the point as fast as possible. Be sure though in your blog posts that you don't use insider terminology without a little explaining. Also in your blog don't just talk about reports, make it interesting. No body will wont to sit there and read about reports when they mean nothing to them.
Here is a great article about blogs as well that was put together by Mashable.com. The article is called, "Top 5 Mistakes to Avoid on Your Company Blog."