The fountain is really really pretty in person, but it’s winter, so it isn’t running. Think of it as a sculpture. I’m sorry you won’t get to see it running, which is downright beautiful, but it’s still worth a look-see. It’s called the Tyler Davidson Fountain, and the big central statue’s name is ‘The Genius of Water.’ Just because I think that’s a great name. The fountain is downtown, on the corner of Fifth and Vine. Fountain Square is sort of the heart of the city- people gather there for all sorts of things, or just to step out of work, eat their lunch, get some fresh air.
While you’re there, you’ll be right downtown, and there’s lots of other fun things. Walk down Main Street a few blocks, and you’ll find the Ohio Book Store, which is a very good used/rare bookstore, four or five floors of books. If you’re into books- and from your post I assume you are- you definitely won’t want to miss this. Especially since you’ll be downtown anyway.
Watch for signs- Cincinnati has a parking problem, but there are garages which are only $1 on weekends. There’s one right underneath Fountain Square, and they’re pretty clearly marked with “$1 Parking” signs.
While you’re downtown, if you like modern art, you might like the Contemporary Art Center. The current exhibits are a collection of political art from the 1980’s and a collection by an artist whose focuse is in the relationships of colors. There’s a cool children’s museum there, too, on the top floor, but if you’re there with kids, I’d take the elevator straight upstairs and not take them to the political art from the 1980’s section, which includes a few pieces which might scar them for life.
If you feel like souvenirs, there’s a mall downtown in the Carew Tower. There’s a Cincinnati schlock shop and a decent food court. Just look around the fountain until you see the skywalk and take it past Lazarus and into Tower Place.
The Half Price Books are really all about the same, but the closest one for you will be up Rt 71 at the Montgomery Road exit. Careful- it isn’t the Mason- Montgomery Road exit, it’s further north. I like them a lot, but the ones in Cincy probably are not nearly as cool as the flagship store back in Dallas.
While you’re in Newport, the aquarium is attached to a nice shopping center, pretty standard upscale shopping, but does include a place where you can get enormous $7 martiniti, if you like. Really nearby is the Purple People Bridge, a pedestrian bridge that goes across the Ohio River. Nice views of the water. I think you can get there from the shopping center or its vicinity, though you’ll have to ask around about exactly how.
This is all more than you can do in one day, of course, but it’s some ideas.