CUADCOPTER PID

Friends, I am doing a cuadcopter but I can not stabilize, and values obtube pitch, yaw, roll with FreeIMu library but not how to implement a PID to stabilize my cuadcopter, someone who could help me?

I'd recommend this online course, it covers all this sort of stuff and more:

https://www.edx.org/course/autonomous-navigation-flying-robots-tumx-autonavx-0

thanks, I will review