I would plant the trees in early spring. Check with your county Land Conservation Department (LCD) to see if they have a spring tree sale. I have bought from them with good success (mom has a farm in WI). White cedar will get eaten fast, white pine will get browsed some. Good selections would be red pine, jack pine, and red cedar for poor soils. White spruce is good for average soil, black spruce is good on moist soil sites.