It seems to me that you can't really lvl up very fast with skill books, BUT, do skill books give you other added benefits? My chef lvld to 10 without reading any skill books. Reading the topic on weight gain and calorie levels, I found there were recipes even my level 10 did not have. Does reading the skill books, no matter what the level, give you more recipes? Would that also be the case for different songs, drinks, etc.?