We have chinese water dragons at the store I work at, and they are totally sweet lizards. Very tame, and very handleable. A little skittish when you first reach for them though.
They are diurnal lizards, so you'll need UVA/UVB lighting. There is a lot of debate as to whether or not diurnal lizards actually need full spectrum lighting, but I say err on the side of caution.
Males get to be around 3 feet, and they are quite active, so I'd recommend a 6 foot enclosure. For substrate, bark works well. Make sure they always have a water dish that is big enough for them to get their whole body into.