Lovely park with a series of trails that go from stroller friendly to a challenge for serious mountain bikers. The generous trails are better maintained in the spring, summer, and fall than in the winter, but the park is pretty in all seasons. Ice can be a serious problem; crampons are not totally uncalled for in the most severe winter weather.
There are usually clay tennis courts and parking spots open on the Regent Square end of the park. The Squirrel Hill side is best for kids, with a playground and baseball diamond. I prefer the Point Breeze entrance, which has two nice trails that form a loop meeting in the center of the park (and take you by the Hot Dog Dam/dog park).
People often let their dogs off the leash here. If you have issues with that, stick to the Squirrel Hill side.