I don't want to sound "smart", but maybe you should search first and then ask questions.... There are lots of threads on this (maybe) and you could use the info in them to ask a more specific question instead of getting some of the same responses already given in those threads....
Beginner needs help - paint suggestions http://www.woodcarvingillustrated.co...-work-me-9335/ Bleeding Paint Painting vs Washes vs Natural Look Painting question for Lynn
^^Here's just a few of topics that are somewhat related.
Most caricature carvers use acrylic. A few use watercolor and a few use oils. I like oils best for appearance, but rarely use them because of the smell and clean up issues.
Sealing is a option that many use also. I'd suggest doing some test pieces (as discussed in depth in some of the threads listed above).