shorthanded no limit preflop play

[urbanati]

I just started playing shorthanded after playing about 100k hands at full table 25NL-PL. My VPIP was about 18%-20% there and I am up 5BB/100. At 6-max I do not really know which hands to play and what VPIP is optimal. And more important: which hands to raise with and which hands to call a raise with...
Any advice is welcome!