If you are using essentials do /setwarp [nameofwarp] Its really easy

Uh.. What warp plugin are you using? It can be different depending on the plugin.. Or mod, for that matter >.<
At any point, if you happen to be using MyWarp as the plugin, it's simply /warp create [name of warp] and /warp [name of warp] to warp there.. If you have any other plugin, just look at the place you downloaded it from..