• ROS: an open-source Robot Operating System
  M. Quigley, B. Gerkey, K. Conley, J. Faust, T. Foote, J. Leibs, E. Berger, R. Wheeler, and A. Y. Ng
  Open-Source Software workshop at the International Conference on Robotics and Automation (ICRA), 2009.

Among the ROS tutorials, the following set of tutorials are the most important:

ROS Itself

Navigating the ROS filesystem

Creating a ROS package

Building a ROS package

Understanding ROS nodes

Understanding ROS topics

Understanding ROS services and parameters

Using rxconsole and roslaunch

Navigating the ROS wiki

ROS command line tools

Stage

Using Stage, the robot simulator

Single robot simulation

Gazebo

Installing and starting Gazebo

Rviz

Rviz user guide