Do you mean a SW cookbook or a general cookbook?
I don't go to class anymore so not sure of the ones you can buy there now but I love:
SW delicious days
Saucy secrets
Curry Feast (I think it's called - hardback SW curry book)
For general cookbooks, I've got so many it's really difficult to recommend one without knowing what sort of food you like and how much you enjoy cooking.
My favourites are all the Jamie Oliver ones - I find his food so simple and most are easily adaptable to SW