Move minimap mail icon

[Lej]

What I want to write is an addon that let's you move the minimap mail icon. Either by clicking and dragging or by showing a slider when you click the icon.

I'm not totaly clueless. I did some simple addons like a year ago and have experience with programming. What I don't know is where to start. Where can I find documentation, tutorials etc. I'm having a hard time finding anything useful at all.