Hwang's first book is pretty good on starting hands - you should consider getting it. The postflop part is more ABC tight-ish, though.
Preflop definitely matters in PLO. Many hands don't play well against usual raising ranges, so you want to avoid playing them if there's a high risk of getting raised. Conversely, you want to raise with good hands because bad players will call with these hands that they should fold. It's not like they can call with any piece of trash and get away with it (even though they are less punished than in NLHE).
From early position, you want to play fairly tight. Open most aces and kings, and all premium hands (big suited rundowns and likes). Do not come in for a raise with meh aces if everybody is going to call, knowing what you got, with a lot of money left to bet.
From late position, you can open raise
a lot of hands: any rundown (0 or 1 gapped, and 2 gapped if the gap is not at the top), high cards that are somewhat connected, high card+suited rundown (eg. K567s) etc.
Play tighter from mid position, since the CO/BTN are often going to call or raise. You want to know your opponents; some will often fold if you open-raise, some will 3bet you a lot.
Here's a post about some starting hands I wrote on my blog. Hope this helps.