Hi Michael,
Sounds like you have a great woodland! I bet you have years of wonderful humus built up from those dropped leaves and needles.

I am in similar circumstances and would indeed rake away the top layer of "stuff," then dig up your soil where you want to plant and see what kind of soil is under there. Amend if needed for your particular plants' needs.

Will there be enough sun? I have my asters in full sun and they spread nicely. Columbine gets part sun and does well here. I imagine they will do they same for you. Re-seeders or spreaders might be hindered somewhat by falling tree debris, but easier for you to control that spread. Not sure. I don't know the habits/needs of the others you mentioned.
You could try a little experiment once you get your plants established, rake around some of them, leave the falling leaves and needles around others and see how each fares.
Good luck, sounds like it's certainly worth a try.
Poochella

If you can, run your lawn mower, set on high, thru the leaves to chop them up. Great mulch. Otherwise, I would leave them, although the maple leaves sometimes make for problems.
The alternative, taking them up, will produce lots of weeds!
Choose plants that like your type of soil, don't amend with anything but organic matter. You probably have acid soil but I would check it thru your local extension office. You will find that you will run into alot of roots once you start digging.
Columbine, woodland anemone, asters, daisey's spread well for me, but I'm a whole different climate. Contact your local Wildflower society. They will have a list of plants that do well in your area. They also usually have fundraising sales every year with cheap prices.

Move them aside, plant and put them back.

I raked mine into a big pile, put it thru a shredder and used half to work into the soil and the other half as mulch. My neighbors think I'm crazy for raking up a half acre of leaves every winter, shredding them and then putting them back. But my gardens love me for it.

Why dont you go visit a local park in your area where an example of pristine woodlands can be found.Do you like what you see,would you like your yard to resemble it? Then ask yourself when was the last time someone raked it?

Care to view what you can or can't grow in leaf litter???? It's a crime as to what folks do with leaf mulch (especially oak and/or pine needles). Some of the most beautiful gardens I know, have glorious gardens growing in oak leaf litter here in the East.

No maintenance landscape that I grow empimedum, forget me nots, anemone, astilbe, primrose, columbine, sweet woodruff, etc etc etc.

Take a look

http://www.tk154.photosite com

How shady is the woodland in the spring? Are there more pines than maples/oaks? The fact that Mother Nature is not growing much now and that you have pine needles on the ground makes me think that the pines are omnipresent.

The plants you want to add do best under decidious trees and rely upon the nearly full sun present in the spring before the trees leaf out for growth. They also do better in the part sun/light shade natural forest clearings that exist after a tree falls down. If you try to grow them in the year round shade under pines they will not do well. Leaf litter should enhance growth, not inhibit it but shade is a killer.

If there are some areas with few pines, try planting there first. Don't remove the leaf litter, just move it aside, plant and move it back.

I would burn it.

There are many beautiful flowering plants that grow only in shady woodlands, in the type of ground litter you describe. I wouldn't try to change it in any way because what you have is the natural result of the plants that already grow there. You can't change the ecology of the area without taking out the trees that live there. So removing the ground cover won't do anything except upset that delicate balance. All that leaf cover will replenish itself in the next 12 months and whatever you planted in it's place will be lost. I'd look for plants that normally grow in that type of environment and try to get some started there. Many of these plants are so uncommon, they may be difficult to find, but are well worth it once you get them started.

Cheryl

I have two and a half acres of oak woodlands. I cleared back 100 yards around all my lawn. I ahve hosta and wild /shade flowers growing. If I did not rake the leaves each spring out of the garden I would fight slugs all summer. I also do not like the messy look.