Thank you for all of your advice.. I can't believe I got all of these responses in such a timely manner! I actually had not thought of checking the local bike shop for used bikes. I'd rather get a used bike from a bike shop.. I was checking on both the Pittsburgh and Eastern Panhandle (of WV.. where I currently live) Craiglist sections, and in Pittsburgh it seemed everyone was charging significantly more than what they paid to buy it! And then in my current area, people are really only selling WalMart or Target brand bikes. I wouldn't be opposed to getting a bike from Dick's, but I've just heard so many horror stories of people getting bikes from the big box stores.
I went online and found out that the shop near my school sells used bikes on a regular basis.. so I think that will be my first stop. If that doesn't work, I will check online like many posters have suggested.. it's just hard when you don't know which bike will feel the most comfortable, or ride the best for what I want it for. I was asking the questions because it seems like everything I read contradicts itself... hybird, road bike, mountain bike.. they all seem good and bad for me.
If I had to choose, I think I'd rather choose something that works best on pavement, then worry about hitting the trails later. I know I'm not going to get the absolute best thing on the market because I'm not willing to spend all of my savings, I just want something that will get the job done and allow me to have some fun.
I'm going to compile all of your suggestions into a big list, then head into the bike shop with that as a starting point! Thank you all again.. I really appreciate it!! I'll let ya know how it works out..