The PSR Tutorial website covers all Yamaha keyboards from PSR to GENOS. If there is something you want to know you'll probably find it in here.
http://www.psrtutorial.com
This is what they say about the site:
The PSR TUTORIAL is for owners of Yamaha arranger keyboards, both mid-level (PSR-S975 - PSR-2000) and upper-level (Genos, Tyros5 - Tyros1). Whether you are a professional musician or an amateur home enthusiast, you will find useful information in the hundreds of pages available here. Our focus is on helping everyone learn how to get the most out of their keyboard.
Hugh