Question on making changes to desktop and compiling

[Marco Ricci <marcoricci2012 yahoo com>]

I hope I have posted this on the correct list. I want to get started off with the source code of GNOME 
Desktop and get comfortable with making changes and compiling it.

In particular, if I wanted to make changes to the source code so that the labels below the Desktop icons used 
a font file of my choice, where would I make the change? 

Let us say I also want to test by making minor changes to the behavior of the desktop when the mouse is 
clicked on the label or when the Enter key is pressed when it is in the edit state. In which file(s) and 
function(s) should I modify the code to achieve the above?

Once I make the change, which modules should I compile?

Once again, it is possible that the above can be achieved by changing some configuration file or parameter 
but I'm looking to learn the source code and would appreciate any response that helps me navigate the source 
code.

Thanks,
-Marco