If you're looking for a pub, then the Parkside (on Floyd Street according to my sources) is probably the most famously associated with City. If you're thinking about restaurants and other activities, http://www.manchester.com/index.php is probably a good place to start. Although parts of it aren't terribly up to date, it's easy to navigate and provides a good overview of the city as a whole.
Make that Lloyd St south! It's a big "blue" pub & gets packed on matchdays but is a friendly atmosphere,specialy if you let it be known how far you've travelled for the match! Round the corner,on Claremont Road,there is the Beehive pub...same again really.Also,there are hundreds of bars in the ground itself,but you can't take a pint to your seat.Manchester city centre is only a couple of miles away,less than £5 in a taxi.Which match are you going to,& where are you sat? If you are collecting your ticket at the ground the office is to the left of the Maine Stand,you'll need to get there a bit early as there is usually a queue to pick tickets up.