sneakers

I have never found a pair of sneakers that have actually fit my feet well, and it's not like I have oddly shaped feet, they are actually quite normal. Right now, I just have my sporty-casual-not-really-for-running Puma sneakers at school, which serve me fine for PT.
As I found out today on my run around campus, that these sneakers are only suited for about 15 minutes of running before intense pain creeps into the arch of my right foot. This is fine for now, because 15 mins is about all I should be running, but I imagine soon that 15 minutes will grow to 20..It's clear that I will soon need actual sneakers made for running. I have two pairs of Nikes at home, but my sister, the track runner, insists that Asics are the way to go. I haven't decided, I love the look of Nikes, and the idea of Nike+, but obviously I need shoes that are going to be beneficial to my feet, and not how they look, at least this is what I try and convince myself. Either way, I want to find someone who's completely knowledgeable about running shoes, and talk to them about what shoes are going to support my knee best, etc!

Kayla tells me there are 'tons' of places like this around, adventure anyone?