How far should i tight nut after installing wheel bearing on mercury mystique?

I, this is the second set of bearings that i messed up. I have a 2000 mercury mystique, bearing on one side of front was bad and a some one reemplaced it for me, right away i stared to hear a weird noise when pressing brakes pedal, then it got worse then more noises etc etc, i bought the bearing again and have different guy to do it, car was perfect just for 2 miles, when i turn stearing i heard the rotors making noises, i jaked my car and move tire from top and bottum and it is kind of loose, some one told me when tighting nut after installation you don"t have to over-tight or leave it loose, it's gotta be just right on, otherwise,bearing will broke again, so that's my question, how far should i go when tighting that last big nut? sorry about my bad english, Torque, what's the new word for me.. thanks in advance