If you have a blog, especially if you blog on topics that might be personal or political or contentious, then you may run into trolls. If you are going to blog seriously, then you need to know how to deal with them. This article will help: How To Handle A Troll, and Beat Them at Their Own Game.
While this article is aimed at usenet users, for bloggers, alot still applies. However, one thing I would recommend is that you moderate all your comments. It helps to nip trolls in the bud. Also, I am not sure I care to beat them. I am happy just to see them move along.