Welcome to the MPV forums! have you checked out the Reason 6 video courses here?
There's lots of sound design ones focusing on the different racks/instruments... well worth checking out!
What kind of sound(s) are you trying to create?
I would also recommend the Reason 6 tutorials we have here, as per Rounik's above post
By learning the different synthesis and sampling techniques in Reason, you will get the idea of how to create your own synth lead lines, bass, drums, mixing techniques, etc...