not really a tutorial but a "what's what" sort of explanation of the UF gradient window. found it in my scraps today - I forget what I wrote it for. so there it is, in case it helps someone out. you can ask any specific questions you might have.
the square dots you see there are called pointers. every pointer has a separate hue (rows 1+2+3=4), saturation (row 5), lighting (row 6), and opacity (row 7) - see Purple for more detail on opacity.
Green: opens a color selection window. all that can be done in that window can also be done in the current view, but the selection window is more spacious and easier to use. the window will be specific to the selected pointer and will have nothing to do with the rest of the gradient.
Blue : randomizes the color of the selected pointer. opacity stays the same unless the "purple" is activated (read further for that)
Orange : eye dropper should be pretty obvious. it also lets you select colors from other open UF windows (doesn't have to be a gradient, it can be a fractal too), so it might be useful if you're looking for a previously used color.
Pink: these two are used to add or remove pointers. that should be pretty obvious too.
Purple: this is key to doing advanced stuff in UF. when it isn't activated (and it isn't by default), the opacity is full and separate from the gradient. you can add/remove pointers from the opacity section separately from the rest of the gradient and the two don't have to correspond. however, when you activate this purple button, it links the opacity and gradient together so the pointers move together. so, say, you can have the pink parts on your fractal completely transparent, you activate this and reduce the opacity to 0 on the linked pointer in the opacity section. This helps tramendously if you want to create a mask out of a layer.
The next button that I didn't mark is for smooth curves. it's activated by default. i haven't ever deactivated it because i never needed to. you may want to experiment with it.