Use the following tutorials to ensure that your install of the simulator is running correctly. Links to tutorials within ROS are not provided, so if you are unfamiliar with ROS concepts, please refer to http://wiki.ros.org/ROS/Tutorials for a comprehensive list of things to ensure you have installed ROS correctly, and that you understand some of the topics involved.
Confirm your installation
Compile the release
Launch Gazebo with the CAT Vehicle
Visualize sensor data
Visualizing the CAT Vehicle
Visualizing the CAT Vehicle and Velodyne with rviz
Visualizing the SICK Laser in simulation in rviz
Transform and visualize SICK Laser data into a different reference frame using MATLAB and tf
Moving around
Driving with a ps joystick
Taking a hard left turn
Following a circular path
Generating code from an existing ROS Simulink model
Running hector_slam with the CAT Vehicle
Examine simulator data
Recording with rosbag
Extracting data with the MATLAB Robotics System Toolbox