most of it will compost away, why not just leave on the ground as mulch? You could rent a chipper and chip the woody stuff (avoid poison ivy) then spread the chips on the ground.

I would also suggest getting a field guide to shrubs and tree and trying to identify the unknown brush. Some of them may be native plants worth keeping.

Finally, consider creating a woodland garden that resembles a real forest with multiple small plants and leaf/twig/plant litter on the ground as mulch. The soil will be better if mulched and the mulch will prevent weed seeds from gaining hold. Bare soil is a invitation to weed seeds.

Thanks for the reply. I neglected to mention that the ground right now is a lumpy mess of pine needles and cones from all the fir trees (which I don't mind) covering all sorts of debris that has been tossed back there over the decades. My husband and the previous owners used the wooded area as a place to toss old christmas trees or grass clippings, dead shrubs, you get the picture... It's also lumpy from clumps of clay that were dug up from other areas of our property and dumped back there.

In my clearing, I've discovered a pair of pants, leftover lumber from the construstruction of our subdivision, dozens of beer bottles and cans, several cinder blocks, plastic tubing that went on for yards and yards (finally threw that in the trash!)...

I guess that's more of what I was looking for in help with clearing out the area. It would be so nice to have a natural looking yard without the fear of tripping over an invisible stump or getting caught on a prickly vine. All of the fallen trees will remain along with as much of the pine needles and leaves. I'm just flustered over the number of invasive weeds that require constant spraying to keep down.

Sorry for the awfully long posts.

Check out the responses to my question about Debris Reduction in the soil forum. I have a very similar problem.
Depending on budget you might want to rent or buy a chipper. If the budget is really big, pay someone else to do it.
What I ended up doing for the time-being is sacrificing some parts of the property to debris piles that I continuously add to. I also break up some debris by hand which makes a big improvement. The stuff in the trash bags could be left in the bags for several months and then dumped out again after it is good and rotten. If getting rid of invasives is your goal then bag up and dispose of anything bearing the seeds of the invasives. I let vines air dry to die and then break them up and toss the remains on the ground. The prickly stuff (like multiflora rose) can be left to dry out and then trampled on to break into small pieces.
Things do improve but it takes time.

Thanks, Bob. I'll go find that thread. You hit the nail on the head with your comments and I'll put them to good use. I may take some pictures and post them here for advice down the line.