Mine rests peacefully in the 20% area. The highest I've seen it spike is about 35%. So 20%-35% with 7 Chrome tabs, Skype, MSN, Steam, Sandboxie, and NeXus.
It all depends on how much RAM you have, and what type of graphics card, of course I'm on a netbook which has 924mb RAM, and I operate 2-3 Chrome tabs, skype and RSbuddy, and my CPU stays at like 65%