Like MMK said. Make sure to keep the substrate damp so that the die off of beneficial bacteria is kept to a minimum. If you have live plants, I'd wrap them in damp paper towels to prevent wilting. You can leave them in tank water but, if they're sloshing around, there might be some damage that occurs. The fish can travel in their cups, though you'll want to make sure that they're kept covered. They can get carsick/seasick if they see a lot of moving light/objects.
Take as much of the tank water with you as you can! Especially if you're moving a fair distance. Your fish are adapted to the water conditions in your current location. When you move, the water chemistry will be completely different. You'll need to do small (5-10%), frequent (2-4 times a week) water changes for the first two weeks to a month that you're at your new place so you don't shock their systems too badly.