PLO starting hand requirements & bet sizing

[gklcap]

Of all the variants of poker I've played, the one that stumps me the most is PLO. The game is too board heavy that I have no clue what exactly a good starting hand is. And what I especially don't understand is what hands I'm supposed to be raising with pre-flop. As a general rule, what should I be looking for in the hands before deciding whether to play them or not?

Another doubt I have is about bet sizing post flop. Is it always better to bet pot size or a little less than it in order to build the pot when you have decent holdings?