How to set and protect a spawn area in bukkit minecraft?

Let me guess. You don't care about the answers to this 3 year old question. You just want to post old questions so your "other" account can get best answer.

You have to do something with the files, not in the game itself. Look up some tutorials, they'll tell you how.

Being Admin won't let you do /setspawn the only way you can to that if you change yourself to Owner. To do so go into console and type /manpromote (Username) Owner or its /manpromote Owner (username)
Try both but i think the first one is right…
Then go into the file where you can change how much protection there's at spawn radius (default 16) or you can download world edit and world guard and look up on youtube how to protect land with world guard (you need world edit for world guard to work)