Someone else posted this same question a few days ago -- you may want to look up that post as it also had a lot of good suggestions. One thing almost everyone posted was the need of a tripod. I suggested a variable neutral density filter since there were many great waterfalls and that filter will help capture water flow at a slower shutter speed giving it a more "milky" appearance. Also if someone hasn't mentioned it, a lens/camera bonnet since the waterfalls sometimes will produce a lot of mist.