A map from the Borough will cost you $4, but you shouldn't have any trouble fumbling your way around this relatively small park. As a few points of reference, if you hit a creek, you're at the lower edge of the park and probably want to make your way back uphill. If you hit a large open field, you're at the peak of the park and right by the parking area.
Despite its size, though, the woods feel quite removed from Pittsburgh. A great place for a short run. Here's a suggested 2-mile figure-eight that may or may not roughly track the trails I did with the spouse and hound last weekend:
(click for larger view)