Demystifying Digital Camera Specs.
 

Came across this excellent set of online explanatory videos from Panavision/Canon in 7 parts. N.B. You wil probably need Quicktime insatalled to view but well worth it in my opinion.

Demystifying Digital Camera Specifications Part 1: What?s in a Pixel?


Jonathan.

I don't know if it's against policy, but Chris ought to sticky a link to that series. We've been talking about it here for over a year now, and it's hugely educational and very well done. A bit beyond new folks, but a great resource nonetheless.