Remember : There are 3 ways to use commands!
You have your command, let's say the kick command, there are 3 ways to use prefixes.
!kick - means people will see you using it
/kick - means people will not see you using it
sm_kick - how you use console commands.
When using commands on players, you only need to write as much of their name as the server will distinguish.
To use a command on a player by a steam ID (ex.STEAM_0:0:XXXXXXXX) prefix it with a # symbol. (sm_kick #STEAM_0:0:XXXXXXXXX)
When putting a reason, use quotes to wrap the whole thing!
In the examples below, don't use the <arrows> when writing stuff out, I'm using them to highlight what the extra variables are.
admin - Brings up the admin menu, this actually has all the commands you need right there for convenience :D
kick <player> <reason> - Kicks a player from the server
ban <player> <time in minutes, 0 for forever> <reason> - Bans a player from the server
mute <player> <time in minutes> - Mutes a player from speaking
gag <player> <time in minutes> - Ditto, but blocks their text chat only
silence <player> <time in minutes> - Blocks a player's voice and text chat
happy <player> - Overrides a player's text chat with silly messages
smite <player> - Smites a player
slap <player> <damage> - Slaps a player, damage is optional
slay <player> - Kills a player
Other commands of interest
rr - Restarts a round, meant for broken payload maps, also resets the map time