I encourage you to view these and many more videos on ISO and Noise Reduction:
Mike Browne from photographycourses.biz on ISO Speed Explained
Tom Greenwood from Sydney Portraits What is ISO? Photography for DSLR Beginners
Marlene Hielema from imagemaven.com Camera ISO: When to use AUTO ISO
Tony Northrup from Northrup Photography “ISO: The Ultimate Guide”
- A VERY detailed and well done presentation which even explains where the term ISO comes from
Matt Golowczynski from Wex Photographic How to Master Noise Reduction in Your Camera
Lynda.com tutorials explains using software Lightroom 4: Reducing Digital Noise
Phil Tughan