Wood in Order of Difficulty

Pine
Maple
Spruce
Birch
Fir
Mahogany
Willow
Ash
Alder
Elm
Apple
Hickory
Redwood
Walnut
Oak
Rosewood
Teak
Osage
Cherry
Ebony
Yew
Mistwood
Bloodwood

Please see http://www.olwydd.org/systems/fletching/index.php for more details on fletching.