Finding Owls in MA ?

So my favorite subjects of Summer are gone, the little swallows. But I also like to shoot Hawks, Falcons and especially Owls, If I can find them.
I'm at the local Audubon Sanctuary in Topsfield,MA, but anyone else know of local haunts for any Owls ?
I also want to be able to look for signs of Owls as well. I know it depends quite a bit for which type of Owls, but there must be signs I can look for.
Any help would be greatly appreciated.