Flying Light Twins Safely (FAA_P-8740-66) FAA publication that makes a great study guide.
Memory items for power-loss in twin-engine airplanes (Reciprocating engine airplanes)
AOPA ASF Baron Safety Review Anyone who is going to teach or learn in a Baron needs to read this! Be sure to read the commentary, page 2-18 on the Vmca maneuver and Part 3, at a minimum. Barons are great airplanes but you have to respect them and not push the limits. Know your airplane.
Multi-Engine Safety Review An FAA Wings course that only takes 20 minutes or so to complete. The course includes some good handouts.