Basic settings:
hostname - server name (shown in the server list)
rcon_password - admin password for remote console access
sv_password - password to join (leave empty for public server)
Player & slots:
maxplayers - maximum number of players
sv_visiblemaxplayers - visible slots (used for reserved slots)
Gameplay settings:
mp_timelimit - map time limit (minutes)
mp_roundtime - round duration
mp_freezetime - freeze time at round start
mp_buytime - buy time
mp_startmoney - starting money
Server behaviour:
sv_lan - 0 = internet server, 1 = LAN
sv_cheats - enable/disable cheats (usually 0)
sv_gravity - gravity (800 = default)
sv_airaccelerate - air movement control (important for surf/bhop)
Network settings:
sv_maxrate and sv_minrate - bandwidth limits
sv_maxupdaterate and sv_minupdaterate - update rates
sv_maxspeed - max player speed
Security & control:
mp_autokick - kick idle or team-killing players
mp_friendlyfire - enable team damage
sv_timeout - time before player disconnects