Jupiter does not have a surface like we are used to on Earth is mostly gas and, deeper down, weird stuff like liquid metalic hydrogen, with maybe rocky core way down in the middle below that. So if you wanted to visit Jupiter you would have to be ready to fly and float around int its clouds, which are mostly made of hydrogen and helium. In those clouds are enormous, long lived storms - the best known being Jupiter's giant red spot.

It might be easier to visit Jupiter's moons, some of which are quite large (the biggest, Ganymede, is larger than the planet Mercury). You could not breath, but at least you could stand!

There is more on Jupiter here

http://nineplanets.org/jupiter.html

cheers, Terry