Lets do scale form....
In STEPS....<whole,whole,half,whole,whole,whole,half>......that is the form of your major scale, and there is no other, so start on ANY note...(How about B?) B,C, but it has to be whole so sharp that C..to C#...next is D, but again we need a whole, so again sharp it and get D#...etc...B,C#,D#,E,F#,G#,A#, and back to B...
For minor, in it's different forms, it is different...and for the modes, wholetone, twelve tone etc it requires a bit more study.
Actually there are really great sites on the web....just put "music theory" in your server to get more than you can handle...
John Cont