My son had a touch of nappy rash recently and although we would normally use Sudocreme it can sometimes be too harsh if skin is too sore. The stuff mentioned before, on one of the other tips, from the chemist, a yellow cream, Meta??????? does work very well.
Be careful with wipes too, we only use them when we're out and about as they can aggravate nappy rash, cotton wool and water do the job well enough at home.