Here are a few technical documents which I made. You might find them useful. Keep in mind that suggestions/corrections/complains/complements are always welcome!
My LaTeX templates page has the basis for most of my documents.
Some other technical notes I have contributed to can be found on Pedro Santana's page.
Technical Note: Using Circuit_Macros in Mac OS X (pdf,zip with extras) This document focuses on the setup of the very professional Circuit_macros package by Prof. J. D. Aplevich. This is a very good solution for making professional-looking diagrams, and it works wonderfully with LaTeX.
Technical Note: Powering and Connecting the Gumstix Verdex (pdf) This document offers a very brief overview of the power issues of the Gumstix Verdex modules, as well as how to make custom serial cables for the platform. I wrote this mostly to document how to make the cables!
Technical Note: USB Programmer for Atmel AVR Microcontrollers (pdf,files) (in portuguese) This is a complete tutorial on how to build and program a Atmel AVR USB Programmer, based on the USBasp Programmer. This is currently the programmer used in our research group, as well as the standard-issue for the Digital Control lab kits. (The document is currently hosted at the co-author's homepage).
Technical Reference: Printed Circuit Board Manufactures (pdf) This document has pretty much all of the printed circuit board (pcb) manufactures I have found so far. Very useful for shopping around!
Technical Reference: Printed Circuit Board General Guidelines (pdf) This pretty much summarizes the general rules I follow when designing Printed Circuit Boards with Altium.