What kind of dog is best suited to be trained to track deer? Not to large.?

Just to let you know, most of the ones the other people listed are BIRD dogs, that's right, ones used to point, flush, and retrieve birds. They will not help with deer hunting! Any type of spaniel, setter, or retriever is used for birds!

Some great breeds would include the Scottish Deerhound, the Irish Wolfhound (deer or wolves), the Great Dane, the Bloodhound, the Dogo Argentino, the Rhodesian Ridgeback (used to hunt lion but can be trained for deer), Plott hound, and there are a couple of others that haven't come to my mind.

http://www.akc.org/breeds/working_group.cfm

Pointer (I suppose?), Brittany, Weimaraner, Hungarain Vizsla, Bloodhound, Basset Hound, Beagle, Great Gascony Blue, Deerhound (rather large).

I think "The Rottweiler " is the best for your requirement. This dog is active, intelligent, friendly and very good to track any thing. Go and check brief information on it.

Well my uncle is a hunter and he owns a French Brittany and that breed only gets up to about 35 pounds

Weimaraner is a very smart dog and very good with children. they are also used for hunting.