How to automatically start programs in specific workspaces on start up
Solution 1:
even though you could actually write some script to auto-start any application you want in different X sessions, you may want to have a look at the confgiuration files of your wm (which is?).
to do exactly what you asked, eg, with xmonad (my wm) you simply have to write a few lines, like
className =? "Icedove" --> doShift "3:mail"
if you use compiz, i think there's a plugin to put an application in a specific workspace. so all you have to do is simply to auto-start them.
so please specify your wm :)