Im wondering how to get commands like you see in some of the big server where you do /server and then the world name and it sends you to that world can anyone help?
That's bungeecord, most likely. Please ask them at spigotmc.org /thread Jade necrodoom (tagged you as I know you guys are active here)
Bungee requires Spigot which is like a high performance tuned version of Bukkit, personally I think it's brilliant, I recommend Spigot to everyone.