My wife and I both work full-time, and my wife is also in graduate school, so we decided to take a weekend trip to Philly to get away from some stress and do some of the things that we have talked about for a while. We first stopped at the Reading Terminal Market, which is a large collection of different restaurants and shops, to get some food before starting. There are several museums that are suitable for all ages (Academy of Fine Art, etc.) and also several places that are aimed at children (Franklin Institute, etc.) that can still be enjoyable by adults.
Quick Tips:
Look for deals online before you go. By booking a hotel or making dinner reservations online, you can save considerable money. Also, research what you would like to do... it can make it a lot easier when you are in the city to know exactly where you want to go. Once there, look around for the free newspapers. These have lots of coupons and offers that can save you further money during the trip. Also, don't get too ambitious planning activities. You will always find things you didn't know about but want to go to.
Best Way To Get Around:
Walking around Philadelphia is fairly easy. I would suggest getting a small map of the city, but if you have this you won't have any problems getting around. For longer distances, I suggest either a taxi or bus. If the weather is nice, however, even long walks around the city can be enjoyable.