There are tons of good brand name bikes on CL for relatively cheap. The big thing is getting properly sized. If you don't mind, pick a brand you want to explore, go to a real bike shop that sells that brand, get sized, then keep an eye out on CL for bikes that brand and size. You don't need clothes, but I do recommend a few things.
First, either a padded seat or padded bike shorts that you can wear under regular shorts. Either way,
spandex is your friend. If no
spandex, then extended rides are going to cause a lot of chafing and boxers/underwear turning into thongs. Not pretty.
Second, definitely invest in a simple bike tool and extra inner tubes to be carried with you on rides. Even a short couple mile ride can turn into a nightmare if you pop a tire with no spare innertube.
Third, to go along with the
spandex, a shirt like an under armour material type material if you don't have one. Cotton, summer, and bike riding are a big no go IMO.
You may never get to this point, but I also highly recommend clip in bike shoes if you ever get comfortable enough on a bike for such things, but that's a ways down the line at this point.
The one that Greg likes is the one I
mentioned. They're pricey, but he's definitely right, but they are excellent bike racks. As someone who's owned a couple different types, albeit all that mount the bike using the top tube, I hate them.
