A new table starts of with the first person who sat on the table becoming the dealer and the next player posting the small blind.
A new game on an active table starts with the dealer button moving clockwise to the next player.
The player to the dealer button is required to place the small blind. The small blind is equal to half the lower stake. This is a guideline for determining the blinds and not a strict rule.
At PartyPoker.com the small blind is rounded down to the nearest dollar.
For example - at $5/$10 stakes Omaha 8 or Better per the formula the small blind should be $2.5. Instead, it is rounded of to the lower dollar, so the small blind would post $2. However, as it is just a guideline, the amount of small blind could be set differently at the time of setting up the table. The player to the left of the small blind is required to post the big blind, equal to the lower stake limit.
In a certain scenario it is possible for more than one player to post a big blind in a hand. This is if a new player joins a table at which a game is already going on. The player would get an option of placing a Big Blind at the start of the next hand or wait for his/her turn (as decided by the movement of the button) to place the Big Blind in turn.
All the blinds in Omaha 8 or Better poker are considered live bets and the players who posted them will have the option of checking, calling, raising or folding when the betting returns to their position.
After the blinds have been placed, the down/hole cards are dealt to each active player.
In Omaha 8 or Better, 4 cards are dealt to each of the players, after which the first betting round starts.
The player to the left of the player who placed the big blind starts the betting for this round.
Each player will now have the option to place his or her bets in the first round, which is set at the lower limit of the stake structure.
For example, in a $10/$20 Omaha 8 or Better game, the value of each bet is $10 for the first round. When we say the bets are limited to $10, it refers to a Bet (single bet) of the value of $10, yet a "RAISE" would be $20 - including one additional bet and a call on the bet placed the previous player.
Bets can be placed by playing any of the following options: Bet, Call and Raise. Each player will also have the option to Fold. These options are available to each player depending on the action taken by the previous player.
The first player (left of the Big Blind) to act (in the first round) would have the Bet, Call and Raise options.
Subsequent players would also have the options of Call and Raise.
To Call is to bet the same as what the previous player has bet.
Raise action calls for raising whatever the bet/call amount of the previous player was, and can be calculated based on the value of the previous bet amount.
Every player participating in the hand should place an equal amount as the previous players (including bets, calls and raises).
Untill all players have placed equal amounts in the pot, the betting will continue. The amount and the number of bets a player can place during a betting round are limited.
The number of bets for a particular round of betting is mentioned below, please refer to the section on "Standard Rules" for the limits of the number of bets.
After the first round of betting is over, the Flop (the first three of the community cards) is dealt. The community cards are common to all the players participating in the hand.

After the flop and in each subsequent betting round, the first active player left of the button is first to act.
The second betting round also limits the amount of bets and raises to the lower limit of the stake structure. .

Bets can be placed by playing any of the following options - Bet, Call and Raise.
These options are available to each player depending on the action taken by the previous player. The first player placing the bet would get the Bet option (the player left to the Button).
Other players will get the Call and Raise options only.

After this round the fourth community card is dealt - this is known as the Turn.

The third betting round starts again with the player left to the button, and bets and raises are limited to the upper limit of the stake structure.
Bets can be placed by playing any of the following options - Bet, Call and Raise.
Combinations of these options are available to the player depending on the action taken by the previous player. The first player placing the bet would get the Bet option (the player left to the Button).
After this round the fifth community card is dealt out - this is known as the River.

The fourth (and final) betting round starts again with the player left to the button, and bets and raises are limited to the upper limit of the stake structure.
Bets can be placed by playing any of the following options - Bet, Call and Raise. Combinations of these options are available to the player depending on the action taken by the previous player. The first player placing the bet would get the Bet option (the player left to the Button).

After the final round of betting, it's time for the Showdown, which determines the winner of the pot is and displays all the players' cards (though this is optional for the player, you don't have to show your cards).
Five cards of the total of hole and community cards (two hole cards and 3 community cards) are used for determining the winning hands.
The best high hand automatically wins the "High" half the pot and could win the whole pot.
To win the "Low" side of the pot, however, you must qualify (which is why the game is named Omaha "8 or Better").
Qualifying for the "Low" half requires a five-card hand with different numerical values from Ace through Eight (with the Ace being the lowest).
The best "Low" hand is A, 2, 3, 4, 5 (also known as the "wheel" or "bicycle"). The winning "Low" hand goes to the player with the lowest high card.
For example, a player with a 2,4,5,6,7 would have a better "Low" hand than someone with an A,2,4,6,8. If two or more players have the same high card, the player with the second lowest card (or the third lowest card, fourth, or fifth if necessary) in their hand wins the low side of the pot.
See the set poker hand ranks, which is used for deciding the winning combination.
Ties: In case two or more players "tie" for one side of the pot, they will split that half into equally divided portions.
If there are odd chips, they will go to the person(s) closest to the left of the dealer button (One player winning the "High" side and two players who tie for the "Low" side is not uncommon in Omaha 8 or Better).

1) Straights and Flushes do NOT count against you when qualifying for "Low".
2) You may use different cards in your hand for the "High" and "Low" sides or the same cards for both the "High" and "Low" sides. In a split pot, any leftover odd chip goes to the "High" side of the pot.
3) To determine your hand(s) in Omaha 8 or Better, you MUST play two of your four "down" cards with three of the "up" (community) cards. You may play different cards for the "High" and "Low" sides.
4) A player "scoops" the pot when winning the whole pot (which is the goal of the game).