um, i was gonna attempt to explain... but it's late... I think you'll get a better response if you post under the "guitar basics" part...
About scales, basically if you play something like cmaj, when you move it up 2 fretts (up to fretts meaning in the direction of the bridge, higher notes, I'm not being condicending, it just it was something that confused me when i first started...) it becomes dmaj, and it keeps it's same pattern... basically you'r intrested in the pattern in the scales and the note which the scale starts with (the root note)... the pattern stays the same (well for all of the scales I know anyway... oh whith out venturing into jazz or anything like that).. the scales that you learn are usually one octave scales (eg from C to C), but there are some that are two octave, but again this pattern stays the same, and the name of the scale changes depending on how far up or down the fret it is moved...
Hope this helped...
I'm pretty sure there's someone else who can do a better job of explaining it than i can....