squeeling noise

First of all check the condition of all your belts, (Fan belts, a/c belts, If they look worn or cracked, replace them. If they do not look worn spray some belt dressing on them, that sometimes helps. Also the bearings that run the belts could be worn too. The alternator would be my second guess, the bearings in those can make noise, and usually requre replacement for the noise to stop. Also check the condition of your power steering fluid and belts, if the fluid smells burnt and looks like a dark brown color change it. Like I said, squealing can be alot of things but its most likely the belts.