How to make an Icon Set?

Ok so I have been playing with setting up UI elements such as menus and  action bars ( I.E. click icon on bar, use an ability or attack ) , the problem I am having is probably just a matter of my over complicating  things, however, when it comes to icons in the in game UI, I am a bit lost.

I know the UI uses image sets and there are a number of them in the ../interface/imagesets folder that corrispond to actual .tga images that are basicly a collection of smaller images nested (perhaps embedded is a better term for it) within a larger image that usualy serves as a background or what have you, ( look in your ../sampleworld/ImageFiles directory for an Idea what I mean.

My question is how does one accully MAKE an Icon set like this ?

Man, we really need a UI guy to have a look at the UI tutorials in the wiki and possibly re-write them in greater detail for dummies like me lol

I have been trying to make a button for 3 hours now and I'm more confused now than when I started lol

I followed all the steps changing names accordingly and I still can't get it to show up lol