Just as there are codes of proper behavior in the real world, there are guidelines to follow in the virtual world. Breeching these codes can get you "flammed" or "bombed" as well as other not very nice things.
The biggest rule - DO NOT SPAM!!! See the section "Spam" so you will know exactly what it is and how to avoid it.
Also common sense will tell you, treat others as you would have them treat you.
Don't go into chat rooms or newsgroups "trolling".
Don't forward everything in your inbox to everyone you know.
Observe in silence before commenting in any public area. It will help prevent you from making a fool of yourself.
Write to be understood! In other words, to come across clear make sure your message is easy to read. TURN OFF THE CAPS!!! By leaving the caps on, you are shouting at people and this can get you flammed. Playing with fonts, colors and backgrounds are fine, but PLEASE, make sure it isn't eye straining to read. Too much fancy font or a colored background with a colored text can turn people off if using the wrong combinations - for instance, don't use brigh yellow with a light green or a strong red with a dark blue.
Just as annoying and immature is mixed caps and lowers in inappropriate places. dOEsn'T ThIS sEEm vErY HaRD tO rEAd?
If you follow these basic rules, you should not have any problem. If someone steps on your toes by not following these rules, don't stoop to their level. Ignore them long enough, they leave you alone. An Internet bully is much like a real life bully, their egos are fed by reactions. If you don't react, they get bored and go away.
Flammed - getting hateful responses directed to you.
Bombed - getting your e-mail filled to the point you cannot get anything else (can also apply to your web site)
Spam - unsolicited commercial e-mail otherwise known as UCE
Trolling - making derogatory comments or stirring up unwanted controversy in a newsgroup or chat room (i.e. - an atheist going into a Christian group bashing them as Bible thumpers)