Welcome to the MySensors community @garnser ! The getting started guide has good recommendations to get you started. The ir example lists which parts you'll need for ir communication. The motion detection example lists which parts you'll need to detect motion. I suggest you read the entire getting started guide, since it most likely will save you a lot of time. The forum has lots of extended discussion on both ir and motion, but I recommend that you start small and get the basic examples working before you extend. If anything is unclear, just ask away