Randi Eckstein grilled Elecia White (@logicalelegance) on inertial sensors: when to use accelerometers vs. gyroscopes; gyroscopes vs. rate sensors; how to make an inertial measurement unit; the basics of quaternions and Kalman filters; what products need which sensors (and why).

Other good resources:

• Sensor Wiki (excellent visualizations)
• Guide to using IMU  (step by step practical information starting with ADC capture)
• Sparkfun inertial sensor buying guide (descriptions on what's available and how to differentiate between them)