Not much is going to grow in the woods, you need some light. Berries can be the exception, some need little light to do OK. Raspberries and Gooseberries do OK in low light. The trees tend to suck up all the moisture.
I usually start planting from the edge of the woods out towards the open, when possible. I always figure the roots spread as far as the crown does and start there.
Some plants do better in the dry season than others. One reason I favor Rape, it tolerates dry spells well. Grows up tall and provides cover and it is frost hardy. Young Winter Rape can be good winter feed.
You also have to think about how you are going to protect your planting, especially bushes and trees until they get established. The Deer will eat them as fast as you plant them.
As far as the fallen timber and other forest trash goes, you have to decide about the fire hazard. All that stuff laying around is good cover for many animals. It will also burn easily.
Read as much as you can. I picked up a lot of stuff by trial and error. My Sorghum plot this year was a failure.
My best successes have been Blackberries for Rabbits and Pheasant. Sunflowers for Dove. Dogwood in the wetter places for Deer, half sun. Blackberries and Dogwood will spread quick if you bury some branch or cane ends in the soil. Mixed plots with Corn and Beans was also a big hit. The Beans climb the Corn stocks and then flower, it is actually really pretty,.
I planted Wild Plumes, Vetch and Jerusalem artichoke this last spring. I planted the (Crown) Vetch on naked steep slopes. The Jerusalem Artichoke on the south and west side of a field. Wild Plume does OK in half sun. All of these come back every spring. I've been favoring perennials over annuals for a long time.
Every spring I start hundreds of new plants from the parents in my home garden and plant them on the lease. Or plant seeds I've saved from the previous Autumn.
Jerusalem Artichoke was a big hit with the Deer. The down side is it dies off in the early fall, but comes back from the roots the following spring. You almost have to fence it to let it grow up high enough to survive long, Deer love the stuff.
I've had mixed results with Clover. Rye is OK, but you almost have to mow it.
Have fun with it. Think in years and multi years, even decades. You have a lot to learn if you are a beginner.