Say like I wanted to get the textures for the characters on Killzone or Halo 2, how do I do it? Does anyone know of any sites that already have them or knows how to obtain them or is it impossible? Not trying to break any copywright laws or anything its just that I would like to edit some textures and use for my game that im making! I really want the guns and character models if anyone can get that! Thanks!

That's some treacherous terrain. I don't think you'll find these things readily available, and if you do, using them is a delicate process that I for one don't understand. Your best bet, for a number of reasons, is to do your own work.

First, it avoids the pitfalls of using other people's stuff, especially stuff that's already been used to make millions of dollars. Second, it's a valuable skill to develop, and if you don't have someone on your team who can do it, you should learn to do it yourself or recruit someone who can. Art is a huge part of game-making nowadays.

Third, if you steal the character and weapon models and textures and do the environments yourself, the game will look like you superimposed professional models into an amateur environment, which is just what you'll be doing. It'll look lousy. Consistency beats out quality, especially in the development phase. You could use different colored cubes to represent your characters and weapons, and it would be better than ripping Halo 2 files into it.

If you finish the project, and it's terrific except for the big smiley faces you use for characters, then you are way closer to a winning piece of software than you would be with slipshod code and dynamite bootlegged graphics. In fact, it would probably be a cinch to come on GD.net and post a prief demo to the Help Wanted Forum and say, "This is my game. It's almost done, as this playable demo can show you. I need three skilled modellers with texture skills and some mapping and animation experience to make decent player models to replace these stand-in smilies." I'll bet you would have volunteers and demo reels and offers pouring in, because every aspiring artist wants to have his name in the credits of a finished project. It boosts their curriculum vitae.

Well is there any programs that I can use to make gun sounds and stuff?

Search around google for royalty free sound effects/textures/etc. Taking ANY copyrighted material, even if you edit 99% of it, is asking for legal trouble.

Alternately you could try and talk to other developers who have made their own sounds, then ask permission to use theirs for your project.