My colleague Grant Griffiths, an attorney turned blogging consultant, teaches as course about blogging for lawyers at Solo Practice University.  Grant suggests that before you start blogging, you should research the blogosphere to see what others in your space are doing.

Grant suggests the following tools to start your research:

Bloglines

Ice Rocket

Google blog search

Yahoo Answers

Technorati

Twitter Search

Why is it important to identify others (some of whom may be competitors) before you actually start your own blog.  First, you need to determine if there is any interest in a particular topic.  Several of the tools noted above will show you traffic patterns - in other words, is anyone reading about that topic.

Secondly, as you get into the habit of reading blog posts, you will sense what approaches work and what approaches do not.  Find a few blogs that you like, subscribe to them using your iGoogle or My Yahoo page (and thus learn a little about RSS feeds) and when you do get down to writing your own blog, you won't be starting with a totally empty slate.