My first post - preflop questions

Hey guys, this is my first post on the omaha board and I have a question about preflop play in full ring games. I understand this depends on ones style of play but I was wondering what a recommended VP$P would be for PLO. I have only played at the very low stakes and tend to limp about 95% of my hands and will raise w. 'premium hands' which I consider big pairs, big double suited (pref. ace high),etc.

My first question is : what type of hands should I limp and my second question is: what types of hands should I raise?

And from what positions, lol thats important too.

Thanks guys