I suggest that you get the book:
Kids gone fishin
It is a really great book that can teach the basics of fresh water fishing to young anglers and their parents. I feel this book can help focus your fishing plans.
Do you guys have rods, reels and tackle?
If not you might want to stop by Dick’s sporting goods to check out their selection. I don’t recommend that you get Spincast combos because the reels made in China are junk and will give you fits trying to get them back in working order while your child waits impatiently for you to fix it.
If you are looking ready to fish combos I would suggest the Shakespeare Catch More Fish Trout Spin Combo
As for fly fishing…I would suggest that you get some experience fishing with conventional rods reels and tackle first. Then if you find that you really love fishing then make the investment in getting fly fishing gear which is a lot more expensive than conventional fishing gear.