There have been several (good) suggestions regarding information for new users at first boot :
igknighted said: Ok, I'm not sure if this is entirely within our scope, but I have long thought that this is the biggest thing Ubuntu is missing.
Why isn't there a new user manual/document on the desktop at boot? I feel like it would be very simple to write up a short document explaining some basic Ubuntu tips/tricks and also things like why mp3's won't play.
Well, Good news !
It seems there is a team working on such a project :
https://wiki.ubuntu.com/UbuntuBeginnerTutorial
See also :
http://www.ubuntuforums.org/showthread.php?p=1676638
If you are interested please consider contributing ideas, or better some time, to the project ...