Creativity-to-Go -
http://www.joelheffner.typepad.com/
Among a myriad of other resources, on the left hand side, you
can see Joel's ebook: How to create a teacher blog.
Dive Blog 2004-2005 -
http://www.resco.ca/diveblog/
This is a great example of how a blog works. Pete MacKay is
linking high school and JH students on this project. It could
easily be done for K-3 students on a different level.