I third Ferguson's book. Be aware though that he writes about shooting longbows. Everything is pretty much same/same between recurves and longbows except one important point. Most longbows are shot with a low wrist grip but most recurves should be shot with a high wrist, or at least neutral wrist. You want all, or at least most of, your grip pressure to be right in the throat of the grip when shooting recurves so the limbs react evenly.

Much depends on the individual bow's tiller thoug. But it's not trial and error. The bow will tell you how high or low it wants to be gripped. If you leave your grip really loose and slowly draw the bow, you can feel where the bow wants you to apply pressure with your grip. That little trick works equally well on both longbows and recurves.