> OK.  How experienced does one need to be, and where/how should one
> volunteer?

Everybody can carry a little peeble or a stone that is adequate.
You can start by writing tests for example. Providing feedback and  
bugs, bug fixes....
Or working on bigger aspects. I think that the most important aspects  
is to have a vision
and work on it. For example, I would like to see a better support for  
packages (and I should have a
look at MC2 :)).

Stef