I'm not sure where you're located or exactly what your style is, so it's hard to advise beyond generalities.
It seems to me that you're looking for a flatbar road bike or a "hybrid," the latter being a very loose term usually indicating a hardtail terrain bike with some roadish touches, like narrower slicker tires and maybe different gearing from a true mountain bike. I would say get a bike with a rigid fork and pass up all bikes with suspension forks, especially since you're aiming at the $500 mark.
Make the rounds of your Local Bike Shops and find the friendliest one that's most oriented to budget-minded, pragmatic, novice cyclists like yourself. I wound up shopping most at my local Performance Bike, which is a big chain and kind of a Bike Mart, but hey, if the shoe fits. The one in my town is a very cool, unassuming, low key place. There are some others in my town as well, one being Bike World. That's the sort of place I would look for.
Performance has a big website which makes shopping there very convenient. I almost hate to say that such a trivial thing influenced me, but when you can see all their stock and prices and specs online, it really helps to make a decision.
I wound up with a GT Zum City Bike for $300. Biggest bang I could squeeze out of my buck for my purpose, which is commuting. I was also looking at GT Tachyon flatbar road bikes and Scattante dropbar road and cross bikes in the $400-$600 range. Scattante is like the Performance store brand, I think.
The only Schwinn I seriously considered recently was the single speed Willy for $200. Also comes in a 7 speed derailleur version. The same frame and fork with a 3 speed internal gear hub is called the Coffee. I think these are very sweet cheap bikes if you like an old fashioned steel delta frame with upright bars.
Looked at the Trek 7.1 FX and liked it also. It would do nicely. Saw some Fairdale bikes I wouldn't mind having.
Some people might steer you to ordering from Bikes Direct. For a first and primary bike, I liked going to a brick and mortar shop. Good staff can find out what you want and need and match it to a bike in your budget.