Build Order:
1. Once you have 150 minerals build a Spawning Pool.
2. Once you have 50 minerals build another Drone.
3. Build Zerglings and once the first batch of 6 comes out rush your opponent.
Hints:
To pull this off, you must build very quickly. Using hot keys will make this rush quicker. When you attack go straight
for the Gatherers to halt their income. Keep on sending Zerglings until you kill your opponent or you realize this strategy
will not work. On maps greater than or eaqual to 128x128 build 2 more Drones and then continue process fomr step 1.
Build Overlords to get more Zerglings. This strategy is "almost" unstoppable on a map like "Blood Bath" when playing against
an inexperienced player.
Some other ideas of what to build are:
1. Overlord drops (an excellent idea)
2. Mass Hydras (this is why they call it the Swarm)
3. Lurker rush/Lurker drop (Brood War)
4. Sunken Colonie Offense (This is my personal favorite yet it is a horrible idea vs. a human opponent)
5. Mutas and Guardians(Very powerful)
6. Drone rush(This one will almost never work but, is worth a try)
Some other helpful hints are:
1. Try not to take your opponents base by force (unless you can) otherwise, you will lose several units.
2. Try not to attack through their chokepoint try and get around it some way (i.e. Overlord drop).
3. If you are rushing and they have units in Bunkers etc., run right by them and take out as many Gatherers as possible.
4. If rushing, take your size of the map into consideration. Longer it take you to get there, longer they have to build.
5. If you are getting beat badly save as many units as possible and retreat to your WELL protected base.
6. Don't trap yourself inside your base, leave room for your units to get out of your base.
7. Learn to use hot keys, you will learn to love them!!
8. Use Scourge to take down Carriers, Battle Cruisers, and other air units.
9. Use Nydus Canals to connect to your opponents base (if they are Zerg too) or with your ally.
10. Massing Zerglings and upgrading them fully is extremely helpful.
11. Build several Hatcheries to keep your units coming out quickly.
12. Use the Queens Spawn Broodling attack to kill many units quickly.
13. Use the Defilers Plague and Dark Swarm to protect your attacking units.
The Zerg are extremely weak in a long game (unless in the hands of an expert player) but are very strong in the early game. Try and out number Zealots 4 to 1 in the amount of Zerglings you have. Later in the game get Hydras with upgraded range to counter Zealots or just get air quick. Groups of Zerglings can take out Dragoons very quickly and efficiently. If you ever see a High Templar kill it on the spot as their PSI Storm can quickly take out many of your units. Kill Reavers with Mutalisks or Guardians. 4-5 Scourge can take down a Carrier, use that to your advantage. Sheer numbers will win the game.
The Terran are extremely good defense masters. Be sure to upgrade your Zerglings to chase down Tanks and Goliaths. Also be prepared for a Marine rush. Have several Zerglings and Sunken Colonies to help. DO NOT try and go through there choke-point unless you believe you have enough units to do so. Try and go around them. Dropping is the best thing if you can get through. If your opponent is building only Bunkers for defense and has Tanks but few Wraiths get some Guardians and attack from afar. This is usually an unbalanced game, so be prepared!!
This game is when the best man, actually wins. You will just have to simply build quicker, be smarter, and simply overwhelm you opponent. Good luck, and have fun!!