Using rcon is pretty easy these days, though if you've never used it it might seem a bit daunting.

Any commands listed here should be issued through your console. If you dont know how to do that I'm not sure why you'd have rcon?

When you have rcon to a server, all you have to do is set the rcon_password cvar to be able to use rcon.
Code:

rcon_password XXXX

There is an additional step if you are not currently playing in the server you wish to access. You will need to set rcon_address to the address of the game server, including port.
Code:

rcon_address games.ozfortress.com:27015

Once that is done, you will be able to issue commands to the server by using the 'rcon' command.

Useful commands:

* rcon say "HEY YO I HAVE TEH RCONZ"
* rcon changelevel <mapname> // will force a level change.
* rcon maps * // will show you all maps installed on the server
* rcon sv_alltalk 0/1 // setting this to 1 will allow everyone to talk to each other using both text and voice including spectators
* rcon mp_timelimit X // sets the timelimit of the current map to X. If a round ends with <=5 minutes to go the map ends. (unless maxrounds or winlimit is reached first)
* rcon mp_winlimit X // a team must win X rounds to end the map. (unless timelimit or maxrounds is reached first)
* rcon mp_maxrounds X // map ends when X rounds have been reached (unless winlimit or timelimit is reached first)
* rcon mp_scrambleteams // will randomise the teams. Useful for pugs when no captains step up. May not randomise very well. Run it a few times if the teams remain unbalanced.
* rcon mp_restartgame X // restarts game in X seconds.
* rcon mp_tournament 1 // turns tournament mode on. There are a few changes to the server to make it easier for tournament play. This will be explained for ozfc2, where tournament mode will be required. Stops the map from changing at the end of a match, and allows clans to muck around and reset the server themselves without rcon using the tournament interface.
* **rcon tf_weapon_criticals 0 // turns crits off (defaults to 1 to turn them back on)
* **rcon mp_friendlyfire 1 // turns friendlyfire on; 0 for off (defaults to off)
* **rcon mp_disable_respawn_times 0 // turns respawn times off, 1 for on (defaults to on)

** Please note commands marked with * change the behaviour of the game as valve intended it. It will change the server to be marked as custom until these commands are removed. The server will no longer appear in the standard server browser and will only be accessable by IP or the Custom tab. These commands shouldnt be used unless you know what you're doing and you have a reason to do it. Typical reasons are turning crits off for a pug.

Kicking, Banning and Unbanning:

* rcon users // shows list of users including userid
* rcon kick "X" // kicks by player name. Bit hard to do if the player has a wankername
* rcon kickid userid/uniqueid "message" // kicks player; userid = first 2/3 digits in 'rcon users', uniqueid = steam id
* rcon banid minutes userid/uniqueid [kick] // bans the player for minutes. see kickid for id details. kick is an optional param, if used it will also kick the player. Use 0 minutes for permanent
* rcon unbanid X // unbans the id
* rcon addip minutes X // bans IP address for minutes specified. Use 0 minutes for permanent
* rcon removeip X // removes IP ban