Businesses are now having to deal with employees blogging. Many corporations are instituting Blogging Policies and Codes of Ethics. One good thing about this is that employees know exactly where a company stands in regards to blogging. There have been employees fired at different companies for the contents of their blogs.

You may want to check with your district to see if they have a policy before you start blogging with your classes. Be careful of student privacy as well. First names MIGHT be ok but, to be on the safe side, get district approval first so there are no surprises later!
Charlene Li's Blog: Blogging policy examples