I agree that a 60 to 90mm refractor is often a good choice for a starter scope. I do not know how much money you want to spend or your 8 year old's fervor for a telescope. If you have the money it would not be a bad idea to get a 6" Dobsonian Mounted Newtonian Reflector. Kids these days are a lot more technologically savvy than we were at that age. The larger diameter scope will give very nice views on a whole range of objects, far better than a small refractor, and yet this type of scope is easy for anyone to use.
On the other side of the coin I bought my sister last year a small table top reflector from Celestron which proved to be quite well made and fun to use for less than $100. If your child proves adept at astronomy and wants continue you can purchase a larger scope later on a future Christmas.
Please do not buy a scope from places like Walmart or Costco. The vast majority of these Christmas scopes are poorly built with lots of plastic, middling lenses (or mirrors), and horrible mounts. A poorly mounted (supported) telescope is not a joy to use. Telescope shops generally sell superior equipment built to last. Orion, Scope City, and Opt come to mind but there are many other outlets.
Lastly do you have a pair of binoculars at home? They make for an entertaining and easy way to scout out the sky and learn where things are.
Good luck to you,