Today's strategy is far more general than the speedling rush and this will be a relatively quick post. For protoss, double gating is something that should be done in order to get out units as quickly as possible. It is most often associated with zealot rushing and if need be, an expansion into 4 gate. The term "gating" just refers to Gateways or Warpgates in which the gateways turn into. With a double gate method you generally want to put the two near the front of your base and initiatie the choke point, which I will get to at a later time.
Of course the first building should be the pylon near the choke point of your base, but not on the outside or too far out so that ranged units can attack it. Once you hit 150 minerals, plop down a gateway and continue gathering minerals. Meanwhile keep training probes. Once you hit another 150 minerals, be sure to throw down another gateway. As soon as possible start training a zealot at your first gateway and chrono boost it out. This will prevent any sort of rush on you. From here on out you can decide to start mining gas and throwing down a cybernetics core or continue to pump out zealots. With double gate though, it is very common to do a zealot rush which will generally work well against another toss player or even a zerg or terran if their defense is lacking.
Again, I'll try to put up a video when I get the chance and sort out the whole video process.