BW Liquipedia has some really good builds, It's far more complete than SC2 liquipedia in tersms of builds. I suggest starting with these

http://wiki.teamliquid.net/starcraft/3_Base_Spire_into_5_Hatch_Hydra_(vs._Protoss)
http://wiki.teamliquid.net/starcraft/3_Hatch_Muta_(vs._Terran)
http://wiki.teamliquid.net/starcraft/9_Pool_Speed_into_1_Hatch_Spire_(vs._Zerg)