Squirrels and upland birds (especially with a pointing dog) are great first hunts. 3 kids in, it has become clear to me that dads think about the hunt and the kids think about time alone with dad. So, really any opportunity will do as long as you are patient and focused on the kid's hunt more than yours.
I just saw this thread and it's a topic I've thought alot about as my kids have begun hunting. I have two sons hunting now. One is 13 and the other is 11. They both started around 10. I think that most of the advice you've gotten is very good, but there's one thing I'd disagree with. I do not think that upland birds are the way to start a kid hunting. I think that in terms of gun handling skills and safety, this is probably the most demanding form of hunting. There's just alot for a young hunter to keep straight. You have to maintain muzzle control as you're walking all over, pushing through brush, etc, probably with another person right near you. You have to be ready for the flush, keep up with the dog, make shot decisions in a split second and watch out for the dog as you're doing it. It's also more likely that there are other hunters nearby. (hunting over a good pointing dog would be different).
