Load the game with kingpin.exe +developer 1 in the command line.  Then, press ` to show the console, and type in god.

Disable Clipping

Load the game with kingpin.exe +developer 1 in the command line.  Then, press ` to show the console, and type in noclip.

Unlock All Weapons

Load the game with kingpin.exe +developer 1 in the command line.  Then, press ` to show the console, and type in give weapons.

Full Ammo

Load the game with kingpin.exe +developer 1 in the command line.  Then, press ` to show the console, and type in give ammo.

Full Health

Load the game with kingpin.exe +developer 1 in the command line.  Then, press ` to show the console, and type in give health.

Full Armor

Load the game with kingpin.exe +developer 1 in the command line.  Then, press ` to show the console, and type in give armor.