High/Low is variant of Omaha where you qualify for half of the pot a 'low' hand and half of the pot with a 'high' hand. The mechanics are the same as in Pot Limit Omaha, but with a few key differences.
Yes, Omaha High/Low is structured identically to Pot Limit Omaha (Omaha Hi) and Texas Hold'em, with a dealer button, a small blind and a big blind. These blinds rotate one position clockwise after each hand, ensuring that all players are affected by them equally over the course of the game.
Omaha High/Low is nearly always played as a limit game, where the size of bet is fixed. Omaha is split into two sizes of bet - big bets and small bets, with big bets typically twice the size of small ones. Pre-flop and on the flop players can only make small bets, and on the turn and river they can only make big bets.
As a basic example, in a €2/€4 limit Omaha High/Low game the big blind would be €2 and the small blind would be €1. During the betting intervals pre-flop and on the flop you can bet or raise €2, and during the betting intervals on the turn and river you can only bet or raise €4.
A player must have five unique cards ranked eight and under to qualify for a low hand. If you have the best low hand you are entitled to half of the pot at showdown. If there is no low hand possible (ie the community cards do not allow it), then the hand can only be contested by high hands. If you have both a good low and a good high hand you can win the entire pot (a 'scoop' - the Omaha8 players' dream!). If you share an identical low with another player, you both have to split the low half of the pot, a practice commonly referred to as 'quartering' (because you only win a quarter of the pot if you have no high).