These are some useful commands you might want to use when running a server. Some of the variables require the map be restarted before taking effect; use the "/map_restart" command to accomplish this.

/serverinfo
Will produce a list of current server settings.

/map
Will load any map with your current server settings.

/map_restart
Will reload current map. You may have to use this command before various server settings can take effect.

/sv_hostname
Change or view the current server name with this command.

/g_gametype
Will display or set the current game type:
"0" - free-for-all DM
"1" - Tournament 1-on-1
"2" - Single-Player
"3" - Team Deathmatch
"4" - Capture the Flag.
Example: /g_gametype "3"

/sv_maxclients
Will display or set the maximum # of players on a
Example: /sv_maxclients "10"

/timelimit
Displays or sets the server time limit.

/fraglimit
Displays or sets the server frag limit.

/bot_minplayers
This command can be used to keep a server populated with random bots when empty. Bots are kicked when players join. Example: /bot_minplayers "4"

/addbot
Can be used to manaully add bots to a game.

/kick
Will kick any specified player from the game.

/g_gravity (default: 800)
Set or display the world gravity with this variable. (Lower number is less gravity.)

/g_speed (default: 320)
Set or display player running speed with this variable. Setting to 1000 will produce highly interesting results.