Leaf identifying help!!! Please!!

I have a project for biology on leaves/plants.
We have to identify 10 leaves/plants that we have picked.
I tried many dichotomous keys already, but they don't help much.

Here are the clues [at this website] that I think might help you identify them:
http://en.wikipedia.org/wiki/File:Leaf_m…

leaf 1. shape & arrangement: elliptic
margin: entire
venation: reticulate

leaf 2. shape & arrangement: obtuse
margin: ciliate
venation: pinnate

leaf 3. shape & arrangement: lobed (many)
margin: crenate
venation: palmate (i think)

leaf 4. shape & arrangement: trifolate/termate
margin: pinnate
venation: dentate (it's close to it...i think)

please help me! i've tried many ways to identify them, but i can't seem to get it.

You should have posted pictures of the leaves you have collected if you want identifications. Start with the local trees that you know the common names. Look up the common names using Yahoo or Google and see if the pictures provided match your collected leaf. The scientific name should be given in the source. For example, chinese elm has this link: http://www.cirrusimage.com/tree_Chinese_…
A very good closeup photo of the leaves of the tree is given.