Could be any number of things like upper or lower A frame bushings or a dry upper or lower ball joint or a dry outer tie rod end. The best way to find out is too take small cribb blocks or jack stands , jack the car up place the blocks / jack stands as close to the lower ball joint as you can get them and set the car down on them that will unload the suspension, remove the front tires for better access , have someone start the car and turn the steering wheel from side to side while you listen , first on one side and then on the other, use a really long screwdriver like a stethoscope to locate where the squeak is coming from, listen to each part of the front end until you find where the squeak is. That's the way I've done it in the past and it's worked pretty good, I hope that helps you and good luck.
PS; be sure you use extra cribbing blocks under the jack pads of the car you can never be too careful.