The first few sections of the Arduino Tutorials have been placed up on the ROBOTC wiki. The vast potential of the Arduino means that it is possible to use it to control just about any platform. As such, we have made several sections for the basic tutorials to help get you started.
We currently have a section for the Parallax BoeBot, a section for using the LEGO hardware platform with the Arduino, and a section for using the VEX hardware platform with the Arduino. We also have plans to develop tutorials for the TETRIX hardware platform in the near future.
As it stands, we currently have tutorials to show you how to use the Arduino to control LEDs, control continuous rotation servos, regular servos, and how to use switches, and we have several more topics in the works.
You can find the full list of Tutorials at http://www.robotc.net/wiki/Arduino_Projects or go directly to the individual platform section using the links below. Keep in mind that ROBOTC for Arduino is still in development, so the content of the wiki tutorials may change frequently – so stop by often!