tree planting guidelines

I just ordered a bunch of seedlings. Yes, I know Paul is big on planting from seed, but apparently my thumb isn't that green. I can get a seed to sprout, but it seems to die soon after. So I ordered some black locust, mulberry and American plum trees, they're supposed to be around 20 inches tall when I get them.

Are there any hard and fast rules for planting them? I've read not to plant them deeper than the original root line. Is it a good idea to make a big hole and fill it with topsoil so it has a nice area of non-compacted dirt or will that make for a weak root structure later on? Any certain time of year that works better than others? I'm in zone 7 and my soil is mostly a sandy loam if that helps any.

Thanks for the input!

Fall is the best time to plant followed by early spring. The shorter/younger the tree the better. The seedling cost $2-$3 each.
You can get alot from these guys. http://www.burntridgenursery.com/nutTrees/index.asp?dept=3
Go ahead and get some more species.

This is what I have in my backyard https://docs.google.com/spreadsheet/ccc?key=0AjpWBJwPQ0nMdEpjV1AwcVJ0dGFZbnVpVEw0RlFQR0E
Its a tiny lot so my canopy height is a mere 10ft, LOL

Big thing is not to 'slick" the sides of the hole, or the tree wont root thru the hard pack.

Dig it, then loosen sides with pitchfork.

big hole not recommended anymore, extra nutrients not recommended.

burying wood, recommended ! as much as you can, as deep as you can.

If you are in dry country, you can dig out in a 2-3 foot circle, and bury some drip line, at least 8 inches below surface.
That way you can water tree, and not water surface weeds. should also consider doing that at distance drip line will eventually be, especially if you are digging in other garden structures later.

Yeah, meaning to get more on the way, that order was from my state nursery, they are native trees. Definitely on the list is a few Linden trees for my bees. Right now about every inch of my property has oaks or hickory on it, many of them dying due to a really bad ice storm in 07 that broke the tops out of most of the trees. Eventually I want lots of peach, walnut and apples among others, but I want to see if I can keep this lot alive first.

I was interested in burying wood and making a hugle-hole if you will, wasn't sure if that was okay to do. So bury like a 3 ft deep by 4 ft round hole and fill with dead wood and topsoil? Should I worry about over watering?