I've had a 1995 Olds Ciera for 6 years and have struggled with the same issue of pulsating brakes and shaking steering wheel. I've had the rotors turned and have bought new rotors. The culprit was the rear brakes. One of the wheel cylinders was leaking very slightly. This would cause the rear brake to grab intermittently. This causes the brake fluid to pulsate and eventually causes a variation in thickness of the front rotors causing the shaking. While the rear brake shoe was gooey, a front brake job would last about six months and the shaking would be back. New rear wheel cylinders, new rear brake shoes and drums, and turned rotors and new front pads solved it. There isn't much difference in the price beween new rotors and drums and having them turned, if you get them from somebody like NAPA-on-line, Rock Auto, or Auto Zone rather than getting them from the repair shop. Buy all of your parts and take them to Les Schwab and have them do a four wheel brake job. They like to sell you all of the parts, but if you take all of the parts in they will still do the job for labor only. "Of course we can't guarantee the job if you supply the parts". If you want the guarantee, buy a four wheel brake job from them. Since I do my own brakes, I redid those front brakes a number of times, including buying new rotors, before a co-worker suggested checking the rear shoes for brake fluid.