http://kidshealth.org/parent/positive/family/net_safety.html

Internet Safety Tips 

Do not give out personal information like what your last name is, or where you live, or what your phone number is. Be careful when your posting stuff on the Internet because as soon as you put it on the Internet, it never leaves. If you are to right an angry e-mail, hold onto it for a day. You may not feel the same way the next day. Be careful on websites that look funny to you. You could possibly receive a virus. You can usually tell when you're on a website like that. Do not copy and paste stuff form websites you didn't put a copyright on. That's plagiarism.