Jayse Hansen was responsible for the design of on screen interfaces in The Avengers. Every time somebody on the Helicarrier looks down at their screen, what they see is something that Hansen built.
Okay, not every time. Every time except with that one guy playing Galaga.
Hansen also designed and animated the incredibly complex HUD display we see during the in-helmet Iron Man shots.
This video gives you a very basic look at how the HUD is brought into being.
For more detail, however, you should check out the oodles of images posted to Hansen's website (thanks to Reddit). Here's a quick survey of the process.
And now you're an expert.