I need help buying a bike, GAF. My 20+ year old piece-of-shit Schwinn that my older brother was given as a gift when he was a young teen finally bit the bullet and I'm tired of sinking more time/money into repairing a shit bike.
So, I don't know where to start. I'm in Illinois on relatively flat ground, using a bike for a few mile commute on paved surfaces five days a week. I'm thinking a road bike with slick tires is my best option, but otherwise, I know nothing about what I'm looking for, not even brands that are decent. My price range is maximum $600 which I suspect isn't going to get me very far, but I'm totally fine with buying a used bike and may even find that preferable.
Can you guys give me even a rough idea of how to go about looking for a bike? Brands to look for/avoid, sizes, styles, etc? I'm completely a newb, and any help would be really appreciated.