Cheat Codes
First off, upgrade your version of MechCommander to 1.8. Then copy your windows.fit file (in the directory you installed MechCommander in) and rename it to ixtlriimceourl with no extensions.
In the Logistics Phase, the mech setup stage the cheats are:

poundofflesh - This cheat gives you 1000000 RP.
rockandrollpeople - Turns off the drop weight limit on the Battalion Transport.
In actual combat, the cheats are:

CTRL-ALT-W - Finishes the mission.
osmium - Makes you invincible to enemy attacks.
lorrie - Repairs your mechs and vehicles gives back wasted ammo.
lordbunny - Unlimited nuke strikes. Hold "b" no quotes and left-click.
mineeyeshaveseentheglory - Reveals the map.
deadeye - Max gunnery skill on MechWarriors.
framegraph - Shows the framerate.

Salvage Mech Code

Code: glennrocksthehouse description below

At the beginning of the first mission, to salvage every mech in the game(you have to destroy them first so they're just junk laying on the field) type in glennrocksthehouse and then DO NOT CHECK YOUR SALVAGE using the ingame salvage tab....if you do you won't get the mechs you blow up...this code works even if the torso blows and takes out most of the mech...have fun harvesting mechs!(this code also works if you're using the artillery code to blow up the mechs)