Phil Torrone from Adafruit sez, "Collin's Lab: Multimeters! The multimeter is your greatest ally when working with electronics. Learn how to measure voltage, resistance, current, & continuity - as well as which meter works best for specific tasks. Here are the previous episodes."
Multimeters considered helpful
I write books. My latest is a YA science fiction novel called Homeland (it's the sequel to Little Brother). More books: Rapture of the Nerds (a novel, with Charlie Stross); With a Little Help (short stories); and The Great Big Beautiful Tomorrow (novella and nonfic). I speak all over the place and I tweet and tumble, too.