Zerg
With zerg the most important thing you can do is have many hatcheries. Every unit that the zerg has comes from a hatchery and if you have tons of them, you can make tons of units. I typically have a large grid of hatcheries so that I can keep a constant army up at all times. The best thing about zerg is that the way their unit creation is set up you can make a large army much faster than any other race. Typical strategies for zerg include rushing and harassing. If you want to be good with zerg you MUST master these. The first strategy is rushing. Rushing is quickly attacking unprepared opponents very early in the game. Zerg are famous for rushing because they can build a minor army the fastest. On small maps rushing is easy because there are only a few locations to where you opponents can be. Have your 8thdrone build a spawning pool and then start pooling minerals. Whatever you do try and have 100 minerals and 2 population points available when your spawning pool completes so you can build zerglings. Overlords take too long to build so having one for your rush is not an option. When rushing, you can surefire your victory by going for their worker units. If you send your zerglings to attack their worker units you can usually kill some before your rush is ended. Most noobs wont have ANY defenses ready and you can end the game with your rush. Moderate to pro players may have a balanced opposing force for your rush waiting for you. The most important thing you can do is not attack their force unless you think you can destroy their force and still have most of your zerglings left over, if not, attack their workers. This is what separates the good players and the bad players. Bad players attack other people armies with their armies. Good players do dirty tactics like focus firing important units/buildings, even if it means losing their army, just to hinder the other player greatly. If you can master your rush, you should be able to end most of your games in less than 5 minutes flat. Even versus pros, a good rush is possible. Rushing will slow you down a bit on your progression, but it should ultimately hurt the opponent much more. A second popular strategy for zerg is harassing because zerg have many fast offensive units. A typical harassment strategy for zerg is to have a few zerglings guard each available expansion. Zerg units can burrow, so that they are hidden until needed.
