This PDF contains a detailed description on adding tree meshes and creating transparent leaves.
I think it's fair to let everyone know how it's done as this is a community project and so many have helped me get this far.
It is a completed work, however I will make additions and revisions at any time.
Here it is in its entirety (edited link - should work now)
http://www.wizardportal.com/optimaiv...Tree_Zones.PDF
link for media to tutorial
http://www.wizardportal.com/optimaiv...emu/mytree.zip
GeorgeS