www.packing.org is always a good resource.
I'll summarize for you, though. Just remember, I'm not a lawyer, and I don't play one on TV.
1. CCW is
verbotten. There is an affirmative defense written into the law, but that is used at trial (as in, you'll be arrested and tried). Also, CCW applies to "any deadly weapon or dangerous ordnance" concealed "on or about [your] person." Needless to say, in a just world that would be void for vagueness. There is legislation pushing its way with glacial slowness through the General Assembly that could change all of this, as well as an Ohio Supreme Court case that could make it all disappear. We'll see.
2. Deadly force is generally deemed OK when it is used to defend yourself or another from serious physical harm. In other words, axe-weilding madman coming right at you? Good to shoot. Guy stealing your DVD player and running away? Not good to shoot.
3. Ohio generally follows the duty to retreat philosophy. If you can get away without using deadly force, you should. All bets are off, however, inside your own home.
4. There is no state preemption of weapons laws, so each little -burg and -ville gets to make its own lists of not-ok weapons and items. AFAIK, only a few have, but be sure to check your local listings. Columbus has one, but court cases have rendered it pretty much null.
Mike