-order a drone
-make your drones to go for minerals(better do it separtely for every drone)
-make drones and send them for minerals till you are 8/9(control)
-order an overload
-order another drone 9/9
-when the overload is ready order drones till you are 12/18
-then when you get aprox. 270 minerals go to build hatchery next to your main. you should be 11/18 after that. don't make more drones at the moment, just gather minerals.
-when you got aprox. 190 minerals go build a pool and a extractor! you should be 9/18
-then start building drones again 3 to 5.
-at the time your extractor is ready send 3 drones there, and take some other to build an Evolution chamber.
-at the time the E.Ch. is ready you should have aprox. 100 gas. Start upgrating melee attack from it immediately. After that remove 2 of the 3 drones from the extractor and send then gather minerals!
-after the pool is ready you should start producing zerglings.
-at 16/18 build an overload.
-when you got another 100 gas upgrate from the pool for faster zerglings.(by that time the upgrate for melee attack will be halfly finished).
-non-stop zerglings! run them to your choke if u r playing on LT.
-after you see the upgrate for Melee attack is nearly finished go with your zergling army in front of your oponent's base and wait there to finish, by that time your zerglings should be running fast
-attack him immediately after the melee upgrate is done.
Situations that may happen:
Remember this strat is ZergVsZerg.
-The other will probably have zerglings, even more than you, but don't be scared! you will smash him even if he morphs lings from 3 hatches!(u have upgrate +1 attack for the lings)
-Other zerg tactic is that he will be playing for mutalisks, but dont worry if you've done the strat right the spire will be nearly finished at the moment you are smashing his army, and will be eASY target after that, even if he gets some mutas, you will have enough lings to eliminate him(usually they dont get mutas by that time, i have won a lot of ladder games like that vs some koreans)
-If he was playing for hydras he would probably have 8 hydras and you will have 30 lings with upgrate for melee attack and faster running GOOD LUCK! If you have any questions and comments mail me at LyuboMilev@yahoo.com! Or you can find me on Battle.net( [69]~sParkY )
PS: I have not written, but you should scout!!!

CreepColony's Opinion: Good strategy.