Boys II Men
Start them early. That's my official stance on getting the kids in the kitchen. I can't remember back that far, so I'm not sure how old I was when I first helped mom in the kitchen. I do remember helping her make stews, soups, and cookies when I was in grade school. In fact, this one time (at bandcamp), I helped my mother make some oatmeal cookies at which I kind of ... ummm ... put a little too much salt in the dough. It called for a teaspon, but my brain saw cup. So I put a cup of salt in the dough.
Adam's famous salt-cookies: guaranteed to give you high-blood pressure. They were awful. But I had fun nonetheless, and I am sure my mother had a good time, too.
Getting kids in the kitchen teaches them math, chemistry, teamwork, patience, being helpful, and most importantly it involves them in what you are doing which makes them happy.
Here's my little Man in an Apron (without the apron) helping his mom make banana bread: