Hi Julie,
Congratulations on your new home!* Willows root so easily you can often just put them in water and they are good to plant in a few short weeks.* Sometimes you can just take cuttings in the spring and put them in the ground to root.* Here's some info about them.
http://hort.ifas.ufl.edu/trees/SALMATA.pdf
Lots of info here on willows. Scroll to the bottom for how to propagate.
http://www.doityourself.com/stry/willows
Do be careful with your selection of fast growing trees as they tend to be softwood, and therefore aren't strong or long lived.* Here's info on trees that might be helpful for you.* These will help you to select northern trees.
http://orb.at.ufl.edu/TREES/index.html
http://www.urbanext.uiuc.edu/treeselector/search.cfm
http://www.mnpower.com/treebook/
More tree info.
http://edis.ifas.ufl.edu/pdffiles/MG/MG08900.pdf
http://edis.ifas.ufl.edu/WO017
http://www.ext.colostate.edu/pubs/Garden/02926.html
http://www.treesaregood.com/treecare/trees_turf.aspx
How to plant, water and mulch.
http://www.arborday.org/trees/video/howtoplant.cfm
http://www.ext.nodak.edu/extpubs/pla...ees/f1147w.htm
http://www.treesaregood.com/treecare/mulching.aspx
http://cals.arizona.edu/pubs/water/az1298/
How to mass plant seedling trees.
http://www.state.sc.us/forest/refplant.htm
If you join Arborday.org for $10 or $15 (I can't remember which it is), you can get 10 free seedling trees.
http://arborday.org/
Here's a site from the Wisconsin Herberiam that shows what's blooming during the different seasons.
http://www.botany.wisc.edu/wisflora/blooming/
Your local extension service should also be a wealth of info.
http://www.uwex.edu/topics/
Newt
When weeding, the best way to make sure you are removing a weed and not a valuable plant is to pull on it. If it comes out of the ground easily, it is a valuable plant.