Odd popping noise and a leak

[BB Turbo]

1993 Nissan 240sx Coupe, base model, automatic, 75,400 miles.

1st off, I just bought the car. My friend jacked it up in the air so we could take a look at it. All underneath on the front of the car there is some sort of lubicant/liquid that has been leaked on. The guy I bought it from said it had a small power steering leak. Could it be the rack? I still haven't checked any of the lines or w/e but thats my first guess. There is also oil all around the edges of my valve cover, so I know that needs to be replaced (gasket I mean).

2nd, when ever I turn the wheel I get a popping noise of some sort. Tie rods? Bushings?

Any help would be appreciated.

[BB Turbo]

Sorry forgot to search. I just did and found a few things that I will try. Didn't really find out anything on the poopping noise, the results were varied.