OK, so i saw that the game does Split Screen? and i was surfing the Forums and i Haven't spotted anything talking particularly about the how to and what not on how to set up Split screen? ... Ive tried to? but having a wireless Keyboard/mouse hooked up with my laptop an other mouse, just basically gives me 2 sets of mouses/keyboards to control one person? I don't really get how to set up the second mouse/keyboard for second player? Third? (i'm wondering because it'd be cool to try and play this with my fams, and friends)

You can't set up several mice and keyboards, there can only be one player with those. The others has to go keyboard only, or use one out of two gamepad slots.
In the Campaign, the Player 1 is always mouse+keyboard, 2 is keyboard, 3 is agamepad, and 4 is a gamepad

You can have 4 controllers at once, actually.

Is that so? Well thanks guys! and for the controller thing, could i like use a 360 controller? ... and Game pad? is that those retro game controllers? Sorry. Pretty noob at most of this stuff.

Xbox360 controllers are actually the best gamepad choice for this game; any other gamepad with a d-pad and buttons can do the job, too, though.
Analog sticks are highly recommended, of course.