My wife and I have backpacked for almost 1500 miles in the last few years, and Daisy's advice is spot on. In our system, we each carry our own sleeping bag, pad, clothes, and water...which we share--that's one way of bit getting separated, if you're drinking the same water!

I carry the tent and ground over, water filter,and the bearcan and food. She carries the first aid kit, cook kit, and toilet kit.

She usually starts out with about 22-24 pounds, depending on weather and clothing. My pack weight varies by the length of the trip, because of the good. I start with about 30 and go up from there. After a few days of a longer trip, I'll start carrying some of her stuff, like the gas cannisters, because the food in my pack is disappearing.

There's more info on how we do things on our website--we my signature line.