Press ~ and type:
impulse 9 - All weapons and mana
impulse 14 - Sheeps
impulse 23 - Torch
impulse 25 - Tomb Of Power
impulse 39 - Flies
impulse 40 - Next level
impulse 43 - All goodies
god - God mode
no clip - No clipping mode
Notarget - Invisibility on/off
restart - Restart the level
sv-gravity** - Change gravity into ** [**=number]
name* - Change your name in* [*=type a name]
give h*** - *** extra health [***=number, i.e. 999]
give 2 - Weapon nr. 2
give 3 - Weapon nr. 3
give 4 - Weapon nr. 4