Need opinions on what's up with my car?

Okay, I have a 1998 Plymouth Neon...I bought it for like 800 bucks...which I think was a really good deal. Anyway, we just got a new rack and pinion put in it, because it was leaking power steering fluid horribly. But now, if we turn the wheel a certain way you can hear this sort of creaking sound...like somebody walking on a creaky floor. There are no apparent problems with the steering or drivability that I can tell...just that noise. What do you think it could be? Also, when we first start the car and use the brakes, they will make a screeching noise. But after we've been driving it for a few minutes, it goes away. We've checked the pads and shoes and everything is fine with that. What are your opinions on what these things could be?