Many people choose to wash carrots, armed with the knowledge that more nutrients are concentrated closest to the skin. But, says food scientist Donald Schaffner from Rutgers University, "I doubt the small fraction of vitamins lost thorough peelings carrots is likely to make much of a difference. I personally peel carrots rather than wash them because I think they look better".
If you are going to wash carrots, however, use a vegetable brush, but don't bother with a 'vegetable wash' product, says Schaffner, because they have not been proven to be effective.
For recipes and tips, see 7 Ways to Cook with Carrots.