I suggest you go to the library at home and obtain a book on each museum you want to visit. Go through the book and see which pieces of art appeal to you, each of you. Read about them, list/map them, and create your own route on what to see. Each of you should have your own route. You don't need a myriad of details to enjoy a piece of art, you just need to be receptive to your own responses. Just go and enjoy a route that appeals to you as fast or as slow as you want. See the pieces that speak to you with the brief background that you obtained at home. As an art history major ...many years ago... descriptions of art are basic, academic BS, generally, given by someone told how to describe and look at the piece. Use your own eyes to see the art, at your own pace.
That being said I love to see the classes of elementary school classes in museums. They are giving kids a love of art at a wonderfully young age with much less of the BS.
My only complaint about RS, at least early on (90's,00's) as I've ignored this topic from him since, is his poor perspective on art/architecture, IMO. This is good, this is not, so he's the last person from whom I'd learn art, especially in Florence. Granted, I am not being generous having not bothered with his recent book on art so maybe he's been educated on it (no one is good at everything. lol so no offense meant.)
More important is to understand the relationship of the Popes to art through the Renaissance, politics, and Girolamo Savonarola. Also, an easy biographical fiction book is The Agony and the Ecstasy, by Irving Stone (not the movie).
I'd suggest a good historical walking tour in Florence instead of in a museum. That should help with the history. But, if you feel you really need a guide, I'd get one in the Uffizi to beat the crowds. Florence is one of my top three cities, if not the top. Have a great time!