I use sav-a-chick electrolyte for their first drink. I got some bantams today that were a bit lethargic but perked right up when I put that water in. Not sure what everyone else uses, but electrolytes work for me!
I only add a tiny bit of sugar for their first water after they arrive from the hatchery if I suspect that their transportation was not gentle. After the first day all you need to do is ensure you clean their waterer and food dish daily and clean off any poop stuck to their butts with warm water. I recently had one chick with a pasty bum that I didn't catch early enough and the poop ended up getting backed up inside her and she was struggling to poop. Apple cider vinegar in the water helps to clear that up if it gets to that point but she was able to clear her vent without anything other than a bum cleaning.