If you're new to having your own Minecraft server, one of the first things you're going to want to learn your way around are the server commands; how to give yourself operator status, how to enable the whitelist and add people to it, how to ban, and so on.
There are two ways to execute commands on the server;
Giving yourself operator status must be done from the console - once you've opped yourself, you can op and de-op other players from inside the game.
There are four levels of Operator;
You can manage the default op level that a newly opped player is assigned from the Server Properties page on your Control Panel > Minecraft.
A whitelist is a filtering method that enables you to allow access only to specific people. When the whitelist is enabled, only playernames that are on the whitelist will be able to access your server.
/whitelist - manages the server whitelist
For more information on formatting the whitelist file, see the whitelist page.
A banlist is a list that specifically blocks access to your server to any name on the list. Even if a user is on the whitelist, if they're also on the ban list, they will be banned from your server.
You can find the full list of Minecraft server commands on the Minecraft Gamepedia wiki - http://minecraft.gamepedia.com/Commands