Revenge of the Witch, by Joseph Delaney

Thomas J. Ward, the seventh son in the family, is going to train with a spook, a person who is a human that kills witches, dragons, boggarts or other evil mythical creatures. Seventh sons are known to see things others don't such as the evil creatures.  As Thomas trains to be a spook he confronts a girl who comes from a family of witches who are a family of deadly and powerful blood witches that feed on blood.

I liked this book because it is dark, creepy and very suspenseful.

Two other books I would recommend are:  Tunnels AND Sword Bird