I'm looking to buy an entry level road bike with a maximum price of about $350. All that I really care about is that it is relatively light and has an easy to use shifting system. I would prefer it to have greater than seven speeds, and would like it to be pretty comfortable. Im getting it only for casual biking around my town, and don't expect to be doing anything more than 15-20 miles on it in once sitting and even that would be a stretch. I'm looking for a good deal on a pretty cheap bike, and since I know basically nothing about bikes i figure i should ask people who do. I'm a 5'8" 18 year old who probably wont be growing all that much more if that helps at all.

If this is in the wrong section feel free to move it, thanks in advance for any help.