During the Social Media Club's workshop in Hawai'i Chris Heuer mentioned IBM's blogging policy. You see, unless you are a start up in the tech-space, having a blog is a relatively new idea. Not only that, but allowing your employees to blog on their own, is downright scary (to some companies).
Some people at IBM put together what they call their Social Computing Guidelines and after perusing them rather quickly - I think they are quite good.
If you are a business that has been around awhile and you've been scared to allow your employees to blog or to have your own blog, take a look at these guidelines and think about implementing them for yourself.
Source: IBM Social Computing Guidelines.