Lots of resourses.
Flash RTS like the first Warcraft games and Starcraft.
Mine resources and build defense systems, research new technologies, train units in order to attack enemy bases and capture resources controlled by enemy.
It's recommended to start with the red guys, "Coempire", it has a short tutorial.
Click on a unit to select it. Click on the map to command unit to move. Click on enemies to command attack. Use the arrow keys to move map. Use the spacebar to deselect units and Esc to stop them. To grab group of units use Box Selection with the mouse left button on hold.