Just when you thought you'd seen the last 2008 Top Ten list, I stumbled across Industrial Control's Top 20 Industrial Control How-To's of 2008. Ok, it's 20 and not 10 and it's aimed at industrial designers; but there are still some useful How To articles here for robotics people too. For example, Basics of the Electric Servomotor and Drive explains the basis of permanent-magnet brush motors and brushless motors. Another interesting How To article is Open-Source Robotics and Process Control Circuit Examples, which describes the use of GNU/Linux-based software to interface with sensors and actuators as well as controlling DC motors and stepper motors. Another How To, The basics of control system design, explains PID, something every robot designer has struggled with at one time or another. There are several other interesting How To articles in the collection so check it out.