1. Don't say things online that you may regret having said in the future. This came from http://www.getsafeonline.org/nqcontent.cfm?a_id=1405. They make a good point on the website when they say "As a general rule, if you wouldn’t say it to your boss or your grandmother, don’t say it online." I think this is super important since people can get caught up in something that may have happened to them and say things they don't really mean.
2. This one comes from the website http://www.microsoft.com/security/family-safety/blogging.aspx, they say "Assume what you publish on the web is permanent." This is another tip to help you consider the content of your blog and whether it's something that you'd want anyone to have access to. I think it's a good thing to think about since many people just think that it's only their friends who are reading their blogs.
3. Use a password! This comes from http://money.cnn.com/2005/04/08/technology/personaltech/blogging/index.htm?cnn=yes and talks about how you do not have to let everyone see your blogs, this would be important if you were only communicating to friends and family and you had no need to share information with anyone other than that.