Hi Joshro,
any hardwood is good - which kind of wood you have access to?
building a sapling bow is maybe for the first bow a little difficult.
But take a look at Black Locust, Elm, Maple, Hazel, Osage, Hickory, HopHornbeam, Dogwood, Yew, RedOak, VineMaple, Ash, Cherry, Apple etc...

Greetz Cord
PS: Maybe take a look at the first and the second thread...