The EFF has a handy guide to blogger rights. It's a bit skewed towards political bloggers, but is still a nice primer. The site also has some good links to EFF classics like How to Blog Safely (About Work or Anything Else).
If you're teaching a course that uses blogs or a course that explores the use of blogs, the EFF's "new" page looks to be a nice resource for students and for class/blog discussions. If admins in your department or university are worried about blogs and legal issues then send them to EFF or summarize EFF's position and remind them of the pedagogical benefits of blogging.