Guides to help you get started with microcontrollers, breadboarding, bootloading, and understanding electricity.
An excellent guide from the Arduino website. However, I would recommend using this Arduino core, so you can use the internal 8MHz clock on the ATmega328 (plus other options)
Getting a brand new ATtiny85 microcontroller to run you Arduino code, on a breadboard
A slide show describing some basic rules and observations on electricity
ICs and other parts that work well on a DIY circuit board
Guides on setting up Eagle, and using it to design our schematics and board layouts.
Getting Eagle setup with the Homemade Hardware github repository
Part 1 on using the Schematic editor to add parts, and connect them together to make your circuit
Part 1 of using Eagle board design editor to design traces, layouts, and board cuttouts
Part 2 on the Eagle schematic editor, using named nets and organizing
Part 2 of using Eagle board designer editor to use groups, ground planes, mirror, and DRC.
Guides on using fabrication techniques and tools when making DIY PCBs at ITP.
How to setup the Bantam milling machine for making PCBs
Milling your Eagle CAD PCB design on the Bantam milling machine
Basic guide on using solder paste, tweezers, and heat-gun to reflow an SMD board