Andrew Birkett's nobugs.org
This is my generic PIC test circuit. It has a button connected to one of the input lines and an LED on one of the output lines. The tan-colored resistor at the bottom is the +5v supply to the PIC, and the blue one is a pull-up for the switch. At the top-left, the two capacitors and resistor are an RC oscilator for the PIC’s clock. Finally, the LED has a current-limiting resistor next to it.
The pinacle of my hardware career was getting the PIC to sample the input line every 1/10th second for about 3 seconds (it only have 36 bytes of RAM) and then having it replay the button-presses out through the LED. The source for the program is here, written in PIC assembler.
At that point, I stopped trying to kid myself that I was a hardware guy and went back to writing software!