Here is an article on IncPlace that has a lot of great information about how to get the word out about your blog. It's called Untangling Web 2.0 and it has information about how you can "build traction for your business". Here are some of the main points.

You'll need a social networking site that has an internal email box. This way you can send messages to your business contacts and they can send messages back to you. Keep messages sweet and short or they may not be read. This is so true because people on the Net don't really read, they just skim, keep this in mind.

Also, make sure you can post bulletins. This is important if you want to notify all your business contacts about something all at once. It's the same as sending an email except that everyone will see it.

Join or create groups that can help your business. Get other people to join your group. Then you can ask their opinions on things relating to your business. You can bet you'll get an honest opinion too. If you joined other people's groups you can get ideas and information from a variety of different kinds of people.

Go to other people's blogs and post comments. Use your signature line to direct them back to your blog. The more people you get information from the better you'll be able to form you business.