A game of Omaha is structured in the exact same way to a game of Hold'em. As in Hold'em, there are four rounds of betting, one before the flop, one when the flop arrives and one each on the turn and river. There is then a showdown and the best hand wins.
Omaha is also played with an identical blind structure to Hold'em. There is always a button (representing the dealer), a small blind and a big blind. Thus the first player who must make a decision in the hand is the player to the big blind's left. In subsequent rounds it is the player to the left of the button who must act first.
For more information on these aspects of the game, please refer to the following links:
