I agree Bill Bulfer's guide is excellent, but perhaps a bit overwhelming for initial training. A couple of basic 757/767 sites that will introduce you to the systems/FMC's are:
http://www.meriweather.com/767/767_main.html
and
http://www.smartcockpit.com/
By the way, Bill Bulfer's website is at:
http://www.bluecoat.org/
He has a forum on cockpit automation and some of the best and brightest folks in the world participate.
And Airbuslad, you will love the 757.......