For the past couple of weeks I have been scoping craigslist for used road bikes. Recently, I came across some bikes that I would like to check out in person. Then, I remembered that I have no idea what I am doing. When I give the bike a look over, what should I be looking for? What are signs that a bike is in bad condition and should be avoided? When I take the bike for a test ride, what should I look/listen for? What tasks should I put the bike through on a test ride? What questions should I ask the seller? Also, some of the bikes I'm looking at have clipless pedals, but I don't yet have compatible shoes. Is this a problem or can clipless pedals still be ridden with regular tennis shoes? If it makes a difference, I am looking at bikes from 2002-2006 or so. All have aluminum or steel frames. Some have a carbon fiber fork. Thanks.