questions about hermit crabs

does anybody have experience with hermit crabs? We bought two and have them in a 10 gallon aquarium, with about 1' of reptile sand on the bottom, plus small rocks covering about half the area (over the top of the sand). So far I've put a few hermit crab pellets and bits of lettuce in a small bowl, one of them nibbled a bit.

some questions i have include: what do they like to eat, how often to give them a bath, do they need misting, is it true that you should immerse them in water for a minute or two for their bath? any advice on shells?

thanks