Basically, this building order allows you to get a good start on your resources before you finally rush with hydralisks. It's biggest weakness is that if you get rushed, you're in trouble. However, if they don't find you early enough to rush you, then you're ok.

1. Normally, you start out with 4 drones, one overlord, and a hatchery. Put the 4 drones working on gathering the nearby minerals, and make a drone. Use the hotkeys if you wish (S-D). Put that drone on minerals too. Keep in mind that if you have enough resources and there are larva around, then you should create something with the larva. The next two you make should be drones and they should go on minerals too.

2. Make an overlord. Once you have enough resources again, make two more drones. One of these drones should build an extractor on the nearby vespene gas source. The other should gather minerals. Continue to make drones and overlords as necessary.

3. Before the extractor is finished, you probably have the 150 minerals necessary for a spawning pool. Have a new drone create the spawning pool.

4. Once the extractor is finished, put two new drones on gathering the gas.

5. When the spawning pool is finished, build a hydralisk den. Build two zerglings (this uses only ONE larva.) Scout using these zerglings. At this time, you should put two more drones on gas. If you didn't have enough gas when you were supposed to build the hydralisk den, then put the two drones on gas first.

6. You should probably have around 300 minerals now. Build a second hatchery at the edge of your base. I highly recommend that you build even more hatcheries especially at other locations where minerals and gas are abundant.

7. Make three hydralisks with once the hydralisk den is finished. Once these three hydralisks are finished, get one of the upgrades in the hydralisk den. (You should get both eventually.)

8. Get ready and attack once you have a huge army of hydralisks. Unfortuately, you can only group a limited number of them together, so you'll have to send them in small swarms at a time. Not a big deal though, and it really frightens your opponent when he sees a second and third swarms of hydralisks after he barely defeats the first swarm.