I’ve been working hard to post screencasts showing you how to use the various parts of your blog. One thing I am not going to screencast is the difference between tags and categories. There is no reason to reinvent the wheel, so, if you want to know what each does (and you DO), go to this great site: Edublogger
Also, you should check-out her fantastic post about how to write your “about” page. It is a great post with helpful tips!