Call of Duty Guide/Walkthrough - PC, PC Walkthrough - IGN
U.S. Campaign: Training  

Training Pathfinder Burning Village Burned Village - Dawn Car Ride Brecourt Manor Chateau POW Camp

Training
Welcome to the life of Private Martin, airborne infantryman. He's young, eager, and not afraid of death, but before Martin can get on the field of battle, he needs to pass basic training. The training is fairly simple and will teach you the commands you'll need to know in order to be a successful soldier. This is a very simple level that should give you no trouble. The commands you need to know are displayed on screen and there are also audio cues to help you out. If you are having trouble, here are some tips to get you through training and onto the field of battle:

Follow the Objective Marker. Can't figure out where the gate is? Don't know where to go next? Look at the Objective Marker on the compass in the lower left of the screen. This will point you the right way.

Don't shoot Sgt. Moody, jackass. As tempting as it may be, shooting Sgt. Moody ends the level and not in a good way. Save your bullets for the Nazis.

Cover when you throw the grenades. The grenade demo may be the only tricky part of training. You need to throw a grenade into each of the two windows and the side door to the left. Be sure to crouch or hide behind the wall after tossing your grenade or you'll take some damage from the explosion. There are more grenades on the table if you run out. 

On to Pathfinder...