go to the Market District and talk to Jensine about THorinir.
Follow that questline untill you reach the tomb at the end (itll be very very obvious) then check behind the coffins for a weapon called "Calebs Grimm Retort" or something similar to that. At level 2 its probably the most effective blunt your going to get, and its a unique looking weapon too.
It's a good mace, but it's not a warhammer and it's magic so he'll need armorer at 50 to repair it.
There's a silver warhammer on a dead goblin in a barrel in the bottom of a cave not far from Bruma. You fall through a hole, land near it, then have to fight your way back out. Don't remember the name, anyone recognize the place? Edit: It's Toadstool Hollow.
You can get a steel warhammer from Jauffre by delivering the amulet and asking for Assistance.
In general there aren't as many good/special blunt weapons available as there are blades.
Mara