Well I would suggest a roach rush but you must know a few things first. This guide will show you how and when to rush with roaches and when you stay away from making roaches. The roach rush can be very powerful and effective if used right but it can also cost you the game if you use it wrong. Right the bat lets talk about the strengths and weaknesses of the roach unit, the roach does very high damage and is also a armored unit, so what does that mean? It means the roach will do very poorly against a marauder because the marauder does extra damage to armored units. The roach is very strong against a zealot, stalker, or marine. I would normally skip right over zerglings and build a roach warren as soon as the spawning pool is done.
So far, Zerg games have been (let's ignore Zerg vs Zerg for this guide) relatively straight forward. Defend from any harassment the Terran or Protoss might throw at you (vikings, phoenix, reapers, immortal pushes), expand and macro up your hydralisk/roach army and try to out expand your opponent. Throw in banelings and sneaky nydus networks plus speedlings and you've got your opponent throwing all their resources into their ground army, trying to wipe out your main army as well as your expansions. A time when Zerg neeed to use Tier 3 units! If the Terran player is heavy on marines and marauders or lots of vikings then you should go ultralisks. When facing Protoss you should watch for immortals and/or air power such as phoenix or void rays in which case you should go brood lords. Immortals are designed for taking down big ground units such as ultralisks and the void rays will pick apart your ultralisks from the safety of air.
Zerg Guide - Ultralisk Strategy
Ultralisks are the ultimate unit a Zerg player can get in a game. Ultralisks cost 300 minerals and 200 gas so they are not cheap and of course they take forever to tech up to because you must be upgraded to a hive before you can build the ultralisk cavern. Ultralisks only hit ground targets and do very well against groups of small units so naturally they are very good against groups of marines and marauders or zealots and stalkers but all in all they do pretty well against any ground unit the enemy will through at you. So it's a good idea to build them if your opponent doesn't have any air units. Of course on the flip side don't build them if you are being attacked from the air, unless you have a lot of corruptors to handle the air. I would also recommend getting the armor and attack upgrades for the ultralisk as they are definitely worth spending the minerals and gas on.
OK so one of the big things that helped me improve my game was learning to micro efficiently. It gave me a huge advantage in battles over opponents who hadn't quite figured out how to command their units correctly. So I've written down a few things about microing that I've learned over the past couple months of playing beta. Note: I pretty much exclusively play Terran so this is kinda geared for them more so. Alright so for starters I always hot key my Command Center(s). I usally set my Command Center at Hot Key (4). This way I can leave keys 1,2, and 3 for specific unit groups. Hot Key (5) I use for my Barracks. This leaves me with 8,9. When I play Protoss I love to have a specific hot key just for my ghosts since their emp is so valuable against the protoss shields. It's important to memorize every single hot key for each units function.
Protoss Basic Build Order
Playing as Protoss is a lot of fun but it can be very frustrating if you don't know the correct starting build order. This guide will show you how to start the game off with the perfect build order for Protoss. You start with 6 probes so get them to work mining the minerals right away. Build probes until the 9th one pops out. Continue making probes until you hit 12 and then start a gateway. You should have about 16 probes when the gateway finishes so start making a zealot and build another pylon. When I play against Zerg I would make build a few sentries so I can block the zerglings from running into my base and killing the probes. Build a colossus if he is massing smaller units, build an immortal if he is using bigger units such as thors and tanks or hydralisks and roaches.