Upon first entering Gidrik from the south the first thing you should do is make your way over to the southwest corner. You'll find Zamora's shop here. She sells potions, and she'll also sell you information about where you can find a map leading to some "unusual metal".
Go north from Zamora's path, past the guardhouse to the inn. Sitting at a table near the northeast corner of the common room is Bryk. He sells horses, which are located in a pen just north of the inn. The inn itself is run by a common innkeeper.
To the east of the inn is a common armorsmith, and just north of that is a common weaponsmith. Those are the only things of note in Gidrik. The storeroom between the horse pen and the weaponsmith contains some nice items, but unfortunately it's guarded. You could push the barrels and crates into an empty house or room, but I personally don't consider the items to be good enough for that much work.