This episode talks about how to use both quadrature encoders and shift registers in your projects as well as offering some examples and application ideas.
74HC595 Serial to Parallel shift register
74HC165 Parallel to Serial shift register
Tutorial: Quadrature Encoders
There are no educational materials that I have links to for the Quadrature Encoders except the article on Wikipedia, however we do have at least one project posted that uses a rotary encoder. Please see the Solder Pot Controller.
Please note that rotary encoders require pull-up or pull-down resistors on their A/B outputs. The common line then goes to the opposite supply rail.
Tutorial: Shift Registers
Probably the easiest way to get started with Shift Registers on the BASIC Stamp would be to download the StampWorks manual from the Parallax website and follow Experiment 23 (74HC595), Experiment 24 (74HC165) and Experiment 25 (Mixed I/O using both ICs).
Once you’ve mastered shift registers (or at least understand them a little better) a more advanced example of using them can be found in the Binary / Digital Clock project on the main website.