2000 GMC Jimmy Steering Wheel shaing

I have a 2000 GMC Jimmy and my steering wheel has recently started to shake while driving. It doesn't make my car move with the wheel, but it concerns me. Also my alignment is off, and pulls to the right. I figure I can fix that with simply getting the car realigned, but the steering wheel has me confused. I know I need new tires and am getting them next week. Would the tires be the problem or am I looking at a bigger issue. Also, when I turn the wheel all the way to one side it makes a crank noise, it's done this pretty much since I got it four years ago so that's not a major concern of mine, but it may help with figuring out the problem.