Here are a few library blogs that would be good models for other libraries. They all have many of the same features, but below each I have commented on just a few that I really thought made the blog different from the others. Check them out!

http://www.madisonpubliclibrary.org/services/blogs.html
This library's blog contains: information on what a blog is, how to post, comment, etiquette, etc., blogs for different age level users, a teen area, book reviews, government information, new library services, events, and resources. It also has a large number of different categories, links, recent comments, archives. You can also register online for programs.

http://www.monroetwplibrary.org/blogs.htm
This library's blog contains: definition of blog and resources, different kids/teen/adult blogs, staff book picks, library events, and blogs on different databases.

http://www.wrightlibrary.org/blogs.htm
This library's blog has much of what the others have but also contains: information on voter registration and blogs on such useful categories as antiques, books clubs, business, consumer information, employment, finances, gardening, health, news, and taxes just to name a few.

http://www.loc.gov/blog/
Now THIS is a blog! The Library of Congress' blog cannot be done justice through my explanation, so go check it out...It contains excellent, informative categories, not only pertinent to the Washington DC area, but to others as well.

http://library.osu.edu/blogs/
Ohio State University's library blog, again, contains much of what the others do, but also library news, manga, peer library assistants, leisure reading, multimedia production space, rare books and manuscripts library, and blogs on each of their college majors.

http://blogs.library.jhu.edu/wordpress/
The Sheridan Library at John Hopkins University also contains much of what the others do, but includes such blogs as learn the library, ask the librarian, library hardware and software, library events and exhibits, tech tips, movies, online resources, publishing, and staff picks.