Starting oak trees from seed
If you want to collect some acorns this fall to plant oak trees, here are some suggestions I've compiled from my own experience and from the sources listed at the bottom of this post:
1. Collect acorns soon after they fall, or (better) pluck mature acorns from the tree when you observe that the acorns are falling. Don't choose green acorns whose caps are difficult to remove -- their seeds are probably not mature. Don't bother with acorns that have lain on the ground for several days, baking in hot, dry conditions.
2. Collect the acorns in a ventilated bag that will preserve their moisture, such as a perforated plastic bag or a burlap or heavy cloth bag. Use separate bags for different species of acorns.
3. Make a note of the species and the location of the parent tree and put it in the bag with the acorns. When you get home, make a permanent record. You'll be glad you did
4. Avoid exposing the acorns to heat or to unusually moist or dry conditions that might kill the seeds. Keep them in the shade after you collect them, and put them in your refrigerator as soon as possible. Don't allow the acorns to bake in the sun, and don't store the acorns in your freezer.
5. If you're collecting the acorns for yourself, plan to plant them right away. Acorns of the white oak family will germinate soon after planting. Acorns of the red oak family will germinate in the spring. (You can store the red oak acorns over the winter, but why bother when you can plant them in the fall?)
6. Remove the caps of the acorns you're planting. Discard any acorns that are malformed, damaged, or light in weight.
7. In the place where you want your oak tree to grow, plant a group of acorns (10 or so) at a depth of about 1.5 to 2 times the size of the acorn. Keep the acorns several inches apart. Choose an open area that is free of ground squirrel activity. After the seeds sprout, you can choose the best of the seedlings.
8. Mark the spot where you planted the acorns so you won't accidentally mow over it next spring. It's a good idea to protect from wildlife damage by surrounding the area with a circle of hardware cloth (wire mesh), embedded several inches into the ground.
9. Be sure to water the spot where you've planted the acorns every few weeks through the winter, if natural precipitation is lacking.
We've had very good luck with planting acorns in the fall, soon after collecting them. It's not difficult to do. Mother Nature does it all the time. And it's a good thing to do -- by propagating the native species in your area, you help to preserve their genes.
More information on acorn collection, storage, and planting:
How to Collect, Store, and Plant Acorns
Acorn Collection and Handling Procedures
How to Grow Your Own Oak Trees
Grow Your Very Own Oak Tree From an Acorn
Planting Oaks - Restoration (includes good diagrams of wildlife barriers around seedlings)