I like to put a couple of hands full of chips and then also a couple big chunks as well. I usually check my chip box ever hour or so and add more accordingly. As far as water goes as mentioned above it depends on how hot you are smoking and how big your water pan is. On my little smoker I might have to add water if I was doing a 6 hour smoke but on my big smoker I have only had to add water once and that was because I started with a small amount of water. I get my water boiling hot before I put it in the smoker. That way you don't have to waste time getting it up to temp.
I'm a little late to the party, but I check my water level everytime I open the door on my gosm. If it needs water, I add it. If not, then I spritz my meat and close the door back up. I use chunks, so I check mine every 1-2 hours and add a chunk or 2 as needed.