The textbook website: Cady & Sibigtroth - Software and Hardware Engineering: Motorola M68HC12. This has a link to a page with corrections to the text as well as source code files for the example programs and other useful information.
Engineering Standards: IEEE Engineering Standards reference An initial site for design standards.
Mathsoft Engineering Standards page Another site for design standards.
Embedded systems design: The Ganssle Group consultants. A wealth of information on designing embedded systems on both software and hardware. There are historical discussions and anecdotes on many issues, including eminent software bug disasters
The RAM Guide: Microcontroller Selector Guide 24 pages. Product info for 8-, 16-, and 32-bit products.
Motorola Transportation Systems Electronics and MCUs in autos. Many system diagrams. How many MCUs are there in a typical car?
How to Destroy Your Computer