Last week I had the pleasure of introducing some experienced teachers to blogging. I hope you are keeping up with checking your Readers once in a while! I want to share a link to a much more extensive list of how-to articles and example blogs than I provided. And, it's a wiki, which means you can add more if it's missing any good ones. (To do so, you would click "EDIT" in the upper-right corner.)
Here's a list of howto and general blogs.
Here's a list of subject-specific blogs.