COMPLETE BEGINNER HERE (FPS Setup Help)

this maybe

http://unity3d.com/support/resources/tutorials/fpstutorial.html

also if you dont want to read the words, some people have done it in youtube video form with the same assets and everything

First step, is to use the "Main Camera" attached to your model aka "Character". Drag the Weapon (Prefab) into the scene in front of the model's Main camera and adjust position towards desired position. Once that's done, you should, locate the model's name in the hierarchy and drag it to the main camera so its position will follow the camera. Then Create an Empty Game Object and call it bullet spawn or something accordingly, this will serve as the spawn where bullets would Instantiate.

There is a standard First Person Controller prefab found in the Standard Assets package that comes with unity. If you import the character controller package into you project:

Assets--> Import Package --> Character Controller

This will import the prefab that you need called "First Person Controller". You can then delete the main camera from your project as there is one as part of the prefab. This will give you the standard WASD movement and mouse look that you need.