UV mapping is a bit like this.
Imagine your objects co-ordinates in x,y,z planes.
so like a point could be 9,2,0
Now UV mapping is taking all those UV co-ordinates from your 3D model and translating them onto a 2D plane: U,V
Once this is done, the texture can be wrapped around the model, where each U,V co-ordinate on the UV map translates back onto a point in 3d.
It's hard to explain. Try looking at the un-wrapped UV map of a cube, then you'll understand whats going on, as you do more, you'll learn what other shapes look like when layed out flat, then it gets easier.
It's just a case of practice. My UV maps were rough as a bears bum until recently, but I've started to get the hang of now!
"It's often better to keep your mouth shut and let people think you're an idiot, than to open it and confirm their suspisions" - Noel Coward
