Loud Squealing noise

My buddy has a 95 Dodge Intrepid. When he first starts driving and when he turns the Drivers front tire squeals really bad, sometimes its really loud, like you can hear it a mile away(not kidding) and sometimes its really quiet but you can still hear it. but when you hit the breaks it stops and when you get over 25 miles an hour it stops. Now every once in a while the wheel will lock up but only for half a second and it comes undone. Any ideas on what this could be? The car has 262000 miles on it and he is going to change the breaks on it soon, just figured i would ask around first. I thought it was the wheel bearing but im not sure. Any and all help is greatly appreciated. Thanks!

Jack up the tire in question off the ground, grab the tire at the 12 and 6 o'clock position and try to rock the top of the wheel toward you while pushing the bottom toward the car, then the opposite. If there's any movement, then the wheel bearing could be toast.