I'll lend a hand...

[matthew.east.ubuntu at breathe.com]

Hi David!! 

Welcome to the team, we really appreciate any help! 

> But before I do, I was wondering if there is a more detailed description
> of the Ubuntu end-users. User profiles, roles, personas or anything that
> talks about what sort of goals, skills, usage patterns and backgrounds
> users may have. I've been hunting around various parts of the Ubuntu
> website looking for such a thing but haven't found anything.

We don't have this to my knowledge. 

What areas are you interested in working on? You can see our projects at 
https://wiki.ubuntu.com/DocteamProjects 

In my opinion, much love is needed on the Gnome Userguide, but plenty of 
other documents also need help! 

Matt