When making userbars.. Help please!

I am making a userbar but I want to use a little image.

Like lets say for instance I wanted to use the runescape skill tree icon...

How would I cut the image out.. then make it so there is no background on the image without loosing much/any of the images quality ?

Can someone please help me.

 

hmm if u r using photoshop

use quik select tool at a low size so it doesnt get much than simply drag into bar..........if ur using that cheat userbar maker than u cant

 

I'm using GIMP