Hitman Contracts:
These codes don't need to be entered in the console. Use a text editor, open up the file: hitmancontracts.ini and insert:

ENABLECONSOLE 1 
ENABLECHEATS 1 

and save. Afterwards, start the game and the cheats during any mission. Also note that Case Sensitivity does matter.

Unlike the other two 47 games, the cheats are now in a menu format. once in the game press SHIFT and ESC simultaneously, this takes you to the cheats menu, use your arrow keys to navigate the menu up and down, then use left and right to toggle the options. 0 = off 1 = on. for codes such as give all or give some, just press enter.

give some - all ammo and most weapons, no secret or hidden weapons 
give all - All ammo and weapons, including hidden and secret 
end level - end level 
god mode - god mode 
infammo - infinate ammo 
invisible - invisible to enemys 

IOIER Bomb 
IOIER Bomb 
IOIER Bomb 
IOIHITALI Boxing Mode 
IOIHITALI Boxing Mode 
IOIHITALI Boxing Mode 
IOIHITLEIF Full Health 
IOIHITLEIF Full Health 
IOIHITLEIF Full Health 
IOIRULEZ God Mode 
IOIRULEZ God Mode 
IOIRULEZ God Mode 
IOIGRV Gravity Mode 
IOIGRV Gravity Mode 
IOIGRV Gravity Mode 
IOILEPOW Lethal Charge 
IOILEPOW Lethal Charge 
IOILEPOW Lethal Charge 
IOIPOWER Mega Force Mode 
IOIPOWER Mega Force Mode 
IOIPOWER Mega Force Mode 
IOINGUN Nail Gun Mode 
IOINGUN Nail Gun Mode 
IOINGUN Nail Gun Mode 
IOISLO Slow Motion 
IOISLO Slow Motion 
IOISLO Slow Motion 
IOIPENNY Unknown 
IOIPENNY Unknown 
IOIPENNY Unknown

Come back to Life: 
When your health bar reaches zero the game will enter a black and white death sequence. If you are able to get four consecutive head shots on four different enemies during this sequence you will receive a small amount of health and return to the game. 

Mini Gun:
The mini gun is held by a patient who is behind the locked doors of a basement room in Mission 1: Asylum Aftermath. The keycard that unlocks the doors can be found during Mission 9: The Wang Fou Incident. It is called Orthmeyers Keycard and is on Lee Hongs desk in his office on the second floor of his mansion. After finding the card, finish the mission and save your progress. Quit to the main menu and replay the first mission. Head to the northern section of the map and turn right in the small room with the red flashing sensor on the ceiling. Pass through the west door and dispose of the patient in order to collect the mini gun.

More Weapons: 
Each of these weapons can be unlocked by completing the mission and achieving the Silent Assassin rating. 
Mission 1: CZ 2000 Dual Pistols 
Mission 2: Micro Uzi Dual Submachine Guns 
Mission 3: Silverballer Silenced Dual Pistols 
Mission 4: Magnum 500 Dual Pistols 
Mission 5: Sawed-Off Shotgun Dual 
Mission 6: M4 Carbine Silenced Assault Rifle 
Mission 7: SG220 .S Dual Pistols 
Mission 8: MP5 Silenced Submachine Gun 
Mission 9: AK 74 Silenced Assault Rifle 
Mission 10: GK 17 Dual Pistols 
Mission 11: Micro Uzi Silenced Dual Submachine Guns 
Mission 12: PGM Silenced Sniper Rifle

Unlock Minigun and Dual Gold Desert Eagles:
In Mission 9- The Wang Fou Incident, look for an hidden Elevator not marked on your Map, and select go down into the basement of the restaurant (or you could take the stairs....). Follow the long corridors until you come to another Elevator, call it up, and select to go into the Mansion. Look around until you find an office. On the desk is Orthmeyers Keycard. Beat the mission with this in your inventory. Now, when you complete the game, select the 'Current Game' option, and replay Mission 1- Asylum Aftermath. Make sure you have these Weapons in your Inventory before you leave the mission to add them to the Weapons Cache.

Level Select:
Open the HitmanContracts.ini file in the Hitman: Contracts directory. Find the line 

DefaultScene=AllLevelsLogos.gms 

and change it to: 

DefaultScene=AllLevelsLevelMenu.gms 

Save the HitmanContracts.ini file. When you start up the game, a menu showing a list of all the missions will appear.