The best way to learn PLO is by playing. I started out by playing a daily freeroll on Power Poker. Really enjoyable game once you get the hang of it a bit. I don't play much of it these days. Try to play hands with 4 cards working together most of the time. (e.g. TJQK double suited) Hands like AJ87 are terrible, stay away from those.
The play is really bad on PokerStars
so try out some of the micro games. They have PLO or PLO8 at 35 past the hour (mostly $3.30 or $4.40 buyin I think) most of the time during the day and some at 5 past the hour. Be sure to check the game type before you join because there are some NL ones thrown in there and that's just bingo.
Not sure if this advice is much good but hope at least some of it helps.
There is a link here
about Omaha strategy. Might be more useful than my ramblings.