If collecting your own seeds, prepare your seed storage early, as seed collection times can vary from year to year. We used a chest freezer modified with an override thermostat to convert it to a refrigerator and stored the collected seeds at 40 degrees F.
Oak, dogwood, chokecherry, wild plum, and other early maturing seeds may need to be collected up to six weeks before the later maturing seeds are ready. Since some of the larger seeds (including the walnuts) mature later and need to be planted first in a direct seeding, the earlier collected seeds will need proper storage. Scout out seed trees ahead of time. When the acorns and later walnuts begin to fall, you will be in a race with deer, squirrels, lawnmowers and desiccation to gather seeds. Seeds need to be kept moist and cool to maintain viability. Soak acorns in cold water prior to storing to chill and hydrate them. If using a freezer modified to work as a refrigerator, set thermostat at 60 degrees (or 10 degrees less than the temperature of the acorns if lower than 60 degrees) and lower it 10 degrees each day until you reach 40 degrees. This will allow the cold to spread from the walls of the freezer to the middle where the thermostat sensor is located without freezing the acorns next to the freezer walls. Look for the freezer/refrigerator override thermostat where wine and beer making supplies are sold.
We used a tool called a Nut Wizard to collect acorns, hickory nuts, butternuts and walnuts. The Nut Wizard saved considerable time and effort compared to picking by hand or raking and it is available in several sizes for various sized nuts. It works best on mowed areas, and we found a good supply of acorns and walnuts on lawns, golf courses and cemeteries. Most people are glad to give you their acorns and nuts if you pick them up.