We had one several years ago. Let's see if I can remember:
Ferrets:
NEED to be descented. Especially males. All there is to it.
Even when descented, they still need to be bathed regularly, once every other day or so. The good part is, unlike cats, they love it.
They eat regular cat food.
They can be litterbox trained.
Train them early not to bite. They use a sort of light mouthing to say "hi", but if not caught, this can quickly turn to biting. A quick thump on the nose with your fingertip and a stern "No!" usually works.
They are unusually fearless. The one we had would regularly face down the cat.
They love to chase anything; balls, vacuum cleaners, whatever moves.