1) Prioritise the real world over the virtual world.
If you are spending more time interacting with people over the Internet than you do in the real world, then you need to seriously curtail your online activity.
2) Your serenity is more important than your involvement on the Internet.
If frequenting a blog or forum disturbs your peace and makes you anxious, uncharitable and/or unkind to those around you, you should simply stop going to that blog or forum.
3) Don't ever say anything on the Internet that you wouldn't say in person.
4) Don't write anything in anger.
5) Don't stereotype people.
6) Take at least one day off a week from the Internet.
7) Always assume the good intentions of others.
If someone writes something that could possibly be interpreted multiple ways, assume the best interpretation.
8) Remember who the real Enemy is.
It is not any one person you meet on-line, but attitudes, misconceptions, prejudices, ignorance, fear...
9) "a spoonful or honey will catch more flies than a gallon of vinegar"
Even "stupid" people believe to be right. Telling them they are wrong, proving them wrong, telling them they are stupid, is not constructive, functional or "helpful", on the contrary.
10) If you want your point of view, beliefs and opinions to be heard, and change the world, don't just go to sites presenting your point of view