In this Blender Game Engine Tutorial #2 I cover:

-How to use the Mouse (Look) actuator to create a FPS (First-Person-Shooter)-Like camera controls using the player’s mouse movement.
-We’ll also make the character move/walk forward using WASD controls

**NOTE: The mouse actuator in the BGE didn’t exist until Blender 2.72. If you’re using an old version of Blender you’ll need to update.

Where to get Blender:

Visit this Blender Game Engine Basics Series playlist: