if you mean a normal server it does not need a plugin. just add yourself to op using the console with this command:
op name
name being your minecraft name.
if it is a bukkit server go to the bukkit plugin list and look for essentials it is the most popular and easiest to use group of commands that has group manager (Group manager is a plugin that is used to make groups like admin/owner/regular/moderator/guest using permissions).
To get a nickname, you have to ask the admin and the need the nickname plugin installed
You can ask the server admin to give you permissions to build on your plot depending on the plugin of creative plots they have.
sorry I messed up my question a bit because I was in a rush. I meant to say What is a good grief protection plugin for MY Minecraft server and I have seen grief prevention.
Up Date Your Minecraft
An admin is a administrator of a Minecraft Server. They are of a higher rank than Moderators.
Place the plugin into the plugin folder and restart the server.
Bucket
manoise
if you are running your own server it can be as easy as asking your server provider to put the admin onto your name.
In order to do this, you should make your server run on CraftBukkit (Download the latest recommended build [DO THIS AT YOUR OWN RISK]) and download a plugin for this kind of labeling.
Well that is quite illegal, first you have to hack the admin's computer, then hack into C; drive. then find the minecraft server file which says admin, then write your name and get out of there. Or just ask the admin to admin you
First you install bukket, then drag the plugin into the Plugin Folder