Have you registered your command in the plugin.yml? And do you have the permission?
Simply put: Craftbukkit is the server client and Bukkit is the API for developers to make Addons/plugins
SideNote: Make sure to check if sender =! instanceOf Player
I'm assuming it is for other players to easily check if the admins are online without searching /list or hitting TAB. This would be a very simple...
Prehaps during onEnable check somewhere(e.g a website/HTML location) if an update is avaliable and then call another class to notify the console...
This would require Spout
Russia isn't a race. Therefore this isn't racist.
A basic bukkit tutorial can be located here: http://stellar.minederp.com/ If you need any help, don't be afraid of using the bukkit IRC
As long as you understand Javas syntax, making simple plugins is simple..or logic based.. Basic bukkit plugin tutorial:...
Link to usage: http://wiki.bukkit.org/Bukkit.yml#aliases
Possibly what you are looking for: http://dev.bukkit.org/server-mods/hardcore/
Separate names with a comma.