Some suggestions for online poker etiquette are:
1. Keep a good connection
It can be very frustrating when you miss out on winning a big pot because you were disconnected, but it is just as frustrating for the other players if you are constantly forcing them to wait while you try to reconnect in the middle of hands.
2. Pay attention to the table.
When it is your turn to act, you are given an allocated amount of time in which to make an action. The software is usually quite generous with the amount of time that they give you; so try to only use the amount of time that is necessary before making a decision. If playing multiple tables slows you down try to limit the number you play.
3. Don't abuse the chat box.
Remember that your opponents are real people too. That is something often forgotten among online players. The chat box should not be used to berate other players at the table or to tell other players about what a great player you are. Keep it fun with light banter, poker and other chat.
4. Don’t discuss hands that you folded.
When you are not in a hand, you should not talk about the cards that you folded while other players are still participating in the same hand. If you discuss what cards you mucked then it could give other players in the hand an advantage if they know what will not come out on the board, so don’t influence play by letting other players know information that they shouldn't. This kind of behavior is frowned upon both in live and online play.