The arena is on Penn St, if I'm not mistaken. (Directly at the center of the 4 food locations mentioned)
DeCarlo's at 228 Penn has some grocery items. There aren't any real full blown grocery stores in town - it's one of the sad facts of American towns. To get to an Acme or a Giant, you have to go to the suburbs.
But speaking of convenience stores, you'all from out of state MUST try Wawa. It's like a 7-11 but so, so much better. Excellent coffee, regular or flavored, healthy convenience foods like fruits and vegies, roll ups, made to order sandwiches - use the computer touch screen, good Philadelphia style steak sandwiches, great service, clean rest rooms. There are no Wawas in Reading itself, but be sure to stop at one on your commute from the airport to your hotel. They dot Route 422. There's one at the Royersford Exit, the Limerick Exit, there's one smack dab in the middle in Douglassville, there's one in Exeter. Watch for the signs. You might think I'm making a fuss over nothing, but people who live in the area will tell you that they are addicting.
Gotta Have Music
I'll add to what Linny said.
Two of our cousins (husband & wife) work for Wawa (not to mention that we're in walking distance of two of the stores), so we're pretty familiar with the stores. Their gas prices are among the most reasonable in the Philly area (compared to the other stations), so it's also a good place to buy gas if you're driving.
The Zamboni Rocks!!!
WaWa also makes good cheap sandwiches!! I love WaWa!!