Heh, my buddy Mike is overstating my qualifications.
Allow me to set the stage: You're going to be staying in an area that is great for seeing the sights, access to public transportation and a couple of Chicago culinary staples: Deep-dish pizza and steakhouses. For most other things, you're going to want to go out into the neighborhoods--not that that's a bad thing, just plan on some travel time.
Transportation: Unless you're going somewhere out of the way, I suggest using the buses that run along Michigan Ave. and Clark St. and the red line El train that runs underneath State St. (nearest stop is at Chicago Ave., a couple blocks south of Water Tower) to get around. Not cheap, but much cheaper than a taxi. Get a CTA transit tracker app for your phone, it'll show you what stations/stops are nearby and which trains/buses are coming when. Here's their site http://www.transitchicago.com/
Assuming you want deep-dish pizza, I agree with Mike's Gino's East recommendation. They just moved to 500 LaSalle St. and changed their menu up, but the classics are still on there. This might be walking distance for you, depending on your exact location and energy level. http://www.ginoseast.com/
Steak: Plenty of great places around you, just depends on your budget and tastes.
If you want a Chicago dog, Portillo's is close and legit (despite the chain-like atmosphere).
What else are you interested in? Chicago really is an incredible place for food, every cuisine and every price level is here in abundance. There's Restaurant Row (lots of "New American" places) about a mile west of the Loop on Randolph St., an Indian neighborhood on Devon Ave. on the northern edge of the city, Greektown west and a little south of the Loop and Chinatown (take the Red Line train south) for starters.
Sights: Make sure you go up either the Willis Tower on the west side of the Loop or the Hancock Tower (very close to where you're staying) for amazing views.
It's great museum weather now.
The Art Institute has a great collection, it's straight down Michigan. The aquarium and the Field Museum of Natural History are also highly recommended and they're right next to each other. Catch the 146 bus heading south on Michigan (make sure it's one that's going to Museum Campus) and it'll take you right there. The Science and Industry museum is further south in Hyde Park, but it's worth it for the U-boat alone if you enjoy history. There's a bus that goes there as well.
I'm not well-versed in the bar scene, but there are lots of joints where you can watch older men with money pursuing younger women on Rush St. (go one block west of Michigan Ave. and then north a few blocks). It's called the Viagra Triangle.
Music: Tons of venues and genres, though none very close to where you're staying, really. What're you looking for?
If you want to check out musical instruments, the Chicago Music Exchange has an insane vintage collection and they'll let you try out anything. Bass Club Chicago is also a great store, particularly for boutique gear.
Metromix is a good spot for seeing what's hot. The Chicago Reader also has good reviews and info: http://www.chicagoreader.com/
The hard copy is free, pick it up when you get here.
Let me know if you have questions!