My whole house is hard wood floors and we have a really hairy fluffy dog, so its double the issues. As for the furniture, we went to Walmart and bought those little plastic round things that you nail in to the bottom of your furnitures legs because the regular feet on the furniture was showing some wear on the floor.
As for the swiffer, I've used it on all our floors, but it doesn't work AS EFFECTIVELY on the real hardwood but works GREAT on the pergo flooring in some of the rooms. Real hard wood, even sealed, allows too much moisture to get trapped and you end up getting some separating in the boards. I have yet to find anything I've liked very much for actually WASHING the real hard wood floors (but mine aren't sealed properly just yet, maybe once sealed well, I'll have better luck).
As for sweeping, a broom will just push the dirt around (or into any little opening in the wood you might have). I have the Dirt Devil vaccuum (its red and looks kinda like a broom) and it SUCKS UP the dirt, so its easier to pick up. The only problem with it is you have to keep it plugged in all the time and it doesn't hold its charge very long. What I end up doing is plugging it in like a vaccuum and using it while unplugging and replugging it in as I go.