There has been plenty written by child development experts about the need for children to contribute to the household labor force. And while we know this, sometimes frankly, it's just so much easier to do the work ourselves. The two biggest obstacles I have run into are underestimating what a child can do and not wanting to hassle with overseeing the learning process. I have since seen the error of my ways and while I'm glad the kids are benefiting from their work, I'm more selfishly pleased by the lightening of my own workload.
Here at the Frowzy house we start kids contributing to the balance of the household from the earliest age. At almost 2 years old, our youngest already has several tasks that she does on her own (scooping dog food into a bowl and delivering it, putting the silverware away in the drawer) and many more that she does with others (putting books on the shelves, putting shoes in the shoe bin, setting the table). My oldest son wasn't enlisted into the household workforce until much too late and every chore became a battle. That was my fault. It was just easier at the time to do the job myself and when I was working I only had 3 hours a day to spend with him and most of that was spent battling him to do homework. So, suddenly he was 10 years old and I expected him to just cheerfully contribute. It didn't work that way. Now, he is 19 years old and still doesn't know how to do the most basic stuff. He has even remarked that the 3 year old does more work around the house than he does.
Now with my younger children, we started young. We don't actually call them "chores." Huh. Now that I think of it, I don't know what we really call them. "Work that needs to be done", I guess. The best way I have found to get the kids to cooperate and get down to business is to have a time, usually the morning and after dinner for us, when everyone gets their work done. This leaves us the afternoon free. When everyone is working, it doesn't leave anything else to do and the work makes sense because everyone is pitching in.
The first few times a child has a job to do, I do it with them. This way all the details and nuances of the job can be shown and explained. I have big plans to make really cool and useful 4x6 cards for each job with pictures and detailed instructions on the back. So far I have started taking a picture of what the finished job should look like. (That's probably as far as I will get, too.) This way when they say they are done, I can ask them to be sure the job matches the picture. I have found that the kids' idea of clean and finished is much different from mine.
I'll do an inspection and then ask them to fix any of the little things they may have missed. "You need to make sure you get all the way down to the corners of each pane when you are washing the windows. Now, go finish." Yes, I want each job to be perfect. The first few times at a new job may take some time for both of you, but once the job is learned it goes much more quickly and efficiently. One of the most frequent corrections is putting everything back once they have finished cleaning something. I have to tell them to put the cleaning supplies away or put the rug and trashcan back, etc. As they are getting older, they know more what I expect of a finished job.
And what do I do about whiners? If you complain, you get an extra job added to your list. One time my 7 year old ended up with 4 extra jobs piled on him. It took him two hours to get them done while the other kids went outside to play. He rarely complains now. Usually it only takes 1 additional job to snap them into line.
Teaching a child the proper way to do a job may take longer in the beginning than doing it yourself, but the pay off is huge both for the child and for you.