if you lvl in a party that everyone is friend with one another just make a rule that the skill books will go 1 for each class, starting with archers/thiefs for more xp =P
dont mind with giving away skill books as reward but this need to change after first week to something else cause after that there will be too many skill books around
one more usefull reward for every class is a pot box but this also will only worth something in the first/second week of the server so need to change to something else after that