Lots to do and see as well as plenty of great places to eat. In Oakland, check out the Phipps Conservatory in Shenley park and the Cathedral of Learning (and the international classrooms) on Pitt's campus. Plenty of museums such as Carnegie Museum in Oakland, Heinz History Center and the Andy Warhol museum downtown, Science Center by Rivers Casino, Heinz Field, and PNC Park. The zoo and aquarium are also great options. Live theater may be an option in the downtown theater district. Besides college (Pitt, CMU, and Robert Morris) there is always the Pirates, Steelers, and Penguins. This is the first time in 20 years that the Pirates have had a winning season and hopefully they'll be playing in the post-season while you are there.
Lately, I have been enjoying the shops, bars, and restaurants on Carson Street on the South Side and Forbes Ave in Oakland will have a lot of activity most nights (particularly busy if Pitt has a home football game). Try Pamela's Diner for the best pancakes. Check out Church Brew Works in Lawrenceville for excellent microbrews and food.
No trip to Pittsburgh is complete without enjoying a ride on an incline (Duquesne or Monongahela) to view the city from atop Mount Washington. Check out Point Park at the confluence of the 3 rivers (Allegheny, Monongahela, and Ohio) (actually it is 4 rivers because one is underground).
Hope you hve great time in Pittsburgh