Is there usually a long wait at the DMV?

Depends on the day, never go on Monday from my experience and go sometime in the mid afternoon or early morning and you should be fine.

I agree with Brian. I also don't recommend going on Friday afternoon, either. Mid-week and mid-day are the best times to hit up any of the DMV (thought we call them BMV) locations.

It depends on the location you choose. The Bureau of Motor Vehicles has a number of Cincinnati based Deputy Registrars: http://www.bmv.ohio.gov/31.stm

They also have a regional office in Mount Healthy. If you choose a not-so busy location on a not-so busy day, you can narrow the wait time. Check before you go though. Not all of the registrars offer all BMV services.