The only chore my kids at that age have is cleaning their rooms 3 days a week. Not that they don't do anything else, but nothing else we consider a chore. As soon as they can put things on the counter, they take care of their dishes after eating. After I fold the laundry, they help put it away. Really, just whatever little things I think they can handle, I ask them to do.
The older two started working in the kitchen at about 6. I am not sure how much the youngest can really do though, just because the kitchen is laid out differently in this house and a lot of what I use is too heavy for her to really be able to out away.