PCB Design

As discussed here are a library of links/Resources pertaining to PCB Design.

The resources are quite technical in nature (unsurprisingly!) so please bear this in mind if you are looking for a basic primer. Watch this space.

Books (thanks to gentlevoice for descriptors)

Electromagnetic Compatibility Engineering by Henry W Ott.
A book that combines theory, yet IMO with a very practical orientation. Discusses e.g. the effects of jitter, multilayer boards, detailed on split/non-split ground planes, effects of distances between signal and ground layer, what is needed to ensure high resolution digital layouts, etc.
Sample here

High-Speed Digital Design - a Handbook of Black Magic by Howard W. Johnson
A book with both theory and many practical examples on the effects of inductances, capacitances, vias, sending & terminating resistors, ground bouncing, etc. IMO modestly technical - oriented towards practical use and implications.

Links - These are all pretty heavy reading, typically around digital signals, but with some analog/digital notes

Henry Ott Consultants
Bruce Archambeault
bethesignal

SpeedingEdge
Signal Consulting
Design Techniques for EMC
Analog/Digital Design guide
Design Techniques for EMC Part 1 Circuit design and component choice
Design Techniques for EMC Part 2 - cables and connectors
Design Techniques for EMC Part 3 - filtering and supressing transients
Design Techniques for EMC Part 4 - shielding
Design Techniques for EMC Part 5 - pcb layout and design
Design Techniques for EMC Part 6

Downloads
Saturn PCB Design Toolkit A calculator for pretty much everything to do with pcb design