I raised my weapon skills in Strathomle. In one of the chambers at the end there are trash mobs that will spawn into magic-based NPCs (at low health, don't one-shot them) that are immune to melee. As long as you don't use magic on them you can just keep wacking away. Be careful, if you are in armor - the duribility will decrease during combat (even if not being hit). I just made everyone nekkid, threw down HP regen totems, and judged seal of light. If you don't mind a repair bill, can keep the armor on.

I'm under the impression that in the next expansion weapon skills won't matter anymore.