The following sites contain some useful information regarding the physical sizes of certain digital camera CCDs, pixel sizes in microns, and noise characteristics and gains at different ISO levels.
- Roger Clark's compilation of gain, readout noise, detector and pixel sizes for a variety of digital cameras.
- Gain, readout noise in ADU and electrons, pixel sizes etc for EOS 10D and EOS 20D. Includes a nice set of examples astro-photography images and dark frames.
Other useful links: