The minimap is special, in the sense it's not available to us on the lua end, all we know is that it's a minimap frame object but we can't do anything to distinguish the different yellow nodes that appear, that is handled internally on the C end.
I'd pick another project to chase after if I was you, hehe.
About programming and getting started, my tips are:
1.
http://www.wowpedia.org/Getting_star...writing_addons
2.
http://wowprogramming.com