The rules of Omaha have already been covered in a different section and therefore it is better in this section to talk about some of the etiquette that goes down at a poker table as far as Omaha is concerned. This is concerning things like betting structures, betting and just general things you should know if you plan to play Omaha out in a casino. Some of these rules apply online as well but some of them do not; the difference should be plainly obvious since the rules that do not apply to the online forum are the ones that would be physically impossible to ban or do online.
Omaha is almost as versatile a game as Hold 'Em, although it is not quite as so. The two most popular betting structures for Omaha are pot limit and fixed limit respectively and while spread limit and no limit are played, they are nowhere near as frequent as all four would be for Hold 'Em. You will rarely see a spread limit Omaha game, even in home games and the only place you can really regularly find no limit Omaha would be online. Most of the casinos will really only be about fixed limit or pot limit Omaha.
Just like with Texas Hold 'Em or any other poker variant, it is a good idea to keep the other players happy by viewing your cards only when the action comes to you. Even if some players start to complain about the extra time your move takes, try to ignore them because if you happen to start giving off tells about your starting hands, they will be even angrier than they seem to be at the few seconds of delay that it takes you.
However, another thing to keep in mind as far as Omaha goes is that it is considered very bad etiquette to remove your cards from the table. Since there are four starting cards in Omaha, one less than in draw poker, a lot of players are very tempted to remove their cards from the table and start looking at them and holding them as they would a draw poker hand. This is something you should try avoiding as not only are you going to have problems as far as the other players are concerned (they might accuse you of cheating if you go on a good streak for example), but it might also allow your neighbours to see what you have easier.
If you are playing in home games or really even in some casino games, check-raising is sometimes not allowed. While it is very rare for it to be totally illegal and banned as a tactic, there are many card rooms across the country where in Omaha it is considered to be very bad form. Make sure you are aware of the rules regarding check-raising in your particular card room before you go ahead and use it as a tactic. Remember, the key is to not piss off any of the players that are sitting near you; players that are gunning for other players are very dangerous and the natural variance of the poker game can make them downright scary.