Browsing through various websites I encounter interesting pages, here in the section called "Molecular Concepts in Digital Imaging" you can find several articles about underlying technology used in digital photography. Among those are: Anatomy of a Charge-Coupled Device (CCD), CCD Saturation and Blooming, CCD Noise Sources and Signal-to-Noise Ratio, Digital Camera Readout and Frame Rates and more.

In this articles you will find a lot of technical information about the digital photography. Want to know how light creates a digital image - look at Film versus Digial. There are other articles, like DOF and Diffusion
Demystifying the Confusion, Tones and Zones, Digital Histograms and more. Well, now I am going to read some of those articles myself :)