Well, i'm not from chicago, but i go there a decent bit, so i think i can add some ideas. As for food outside the stadium, you have to have chicago pizza atleast once. I suggest Giordanos myself. I love it. It's about a 45 min wait(depending on how many people are there), but it's worth it. I love Italian, and i'm sure others might be able to suggest something better, but i always try to go to Maggianos when i can. As for food within the stadium, i would stay away from just about everything. The hot dogs are ok, but all in all, Wrigley food is pretty bad. When you go to Wrigley, take it all in. Walk around the outside of the park before you go in, just take in the entire atmosphere. Enjoy yourself, however, if you can avoid it, don't go to the bathroom. It's not real pretty. As for stuff you should see, i guess that depends on the kind of stuff you are into. Chicago has just about everything you could really want. Museum of Science and industry, Natural History, Navy Pier(a little touristy for me, but it gives you a great view of the city), Chinatown is nice, Millennium Park is pretty, and on the north side of the Art institute IIRC. John Hancock Center, you can go on and on.