Instructions
Build a couple of cheap scouting units as soon as your match starts. Protoss players can use Scouts, Terran can send an SCV, and Zerg can use Drones.
Deploy your scout units to different parts of the map. You should send at least one unit to your enemy's base to get an idea of what he is building, but the others can search for pockets of minerals.
Click around the minimap to keep track of each of your scouts until you have made a couple of Vespene discoveries.
Station your scouting units at the geyser until you can push some resources into building a refinery on the site. Remember that these satellite structures are hard to defend and are most effective if captured early in a game.