Read our General Poker Tutorial first.

Omaha Poker
1.) Deal: Four cards face down to each player.
2.) Play: 1st betting round (the highest showing hand starts).
3.) Three cards ("the flop") are dealt face up to the middle of the table.
4.) 2nd betting round.
5.) One more card ("4th street" or "the turn") is dealt face up to the middle of the table.
6.) 3rd betting round.
7.) One more card ("the river") is dealt face up to the middle of the table.
8.) 4th betting round.
9.) Each player makes his best five card hand from two of the four cards he is holding and the table's five cards.
11.) Showdown: The player with the best five-card hand wins. In Omaha 8, the highest and the lowest hand split the winnings, but the low hand must be no higher than 8.