Hey Cheecho,
Welcome to the Shack; there are a lot of helpful people around here!
Circuit City isn't a great place to audition speakers. They usually have a bunch of loud stuff on, things are haphazardly located, and the sales drones are just that: drones ( all right, to be fair, I'm sure there are some good drones out there on occasion ). But see how you went in and you can't even check out something you want to purchase. A big step up from there is Best Buy's Magnolia Hi-Fi/HT centers. They're not the best, but they have a bigger selection of nicer stuff. You can go in there and start to get a feel for what's out there. IIRC, they have Yamaha, Denon and Pioneer receivers ( and perhaps others ). For speakers, they have Martin Logan, Vienna Acoustics, Mirage, Klipsch, Definitive Technology and probably others. If you check out those speakers ( even outside of your budget ), you will get a flavor for what the range in speaker sounds/styles can be -- that group includes electrostatics, direct radiating, bipolar and horns: a wide variety in speaker technologies and philosophies. Some like Brand A and some like Brand B; it's all up to the individual taste.
As far as receiver price, there is a pretty big range out there. If I were going to buy a receiver today, I would really look at the HK 635 at about $600. I've heard good things about the power section ( amplifier ) of the HK, though I've never owned one. I would also consider Denon and Marantz in that price range ( $500-$600 ). I've had a Denon and it treated me well power-wise, as well as feature-wise.
I would probably steer away from Yamaha, as they only allow a fixed crossover point ( can't recall if it's 80 or 90 Hz ), and that further implies that that crossover point is applied to all channels in the system ( i.e., fronts, center, rears are all crossed over at the same frequency, and you can't change it ). With today's super-flexible receivers and processors, that fact alone is enough to make me not even consider Yamaha, regardless of the rest of the package. Oh, be sure that whatever receiver you buy has preamp outputs so that you can add on a power amp in the future if you need to.
If you're going for mainly music and occasional movies and Xbox, I might consider starting with a 2.0 or 2.1 system. That is, forget about the center and surrounds for now. That will allow you to get into a much better main speaker, and that's your critical point for music listening. Depending on your movie requirements, you may also be able to get away without a center channel at all -- if you are able to control where you sit ( i.e., in the center "sweet spot" position ), you can do a "phantom center" mode where all center channel information is pushed to your mains. If you ( or others ) will regularly be out of the center spot, it would be better to have a center channel, and one that matches your mains. I've also found that, if you're not terribly critical about movie listening, it's easy to "save a little" on rears.
Anyway, back to the original point -- if you're mainly interested in music, go with two mains for now, perhaps with a sub ( depending on the mains -- how badly they need it ).
Here are some links:
SVS SCS-01 speakers (<$500/
pr):
http://www.svsound.com/products-spks-scs01.cfm
Vandersteen 2Ce Signature ($1500/
pr):
http://www.vandersteen.com/pages/2Celit2.html
Magnepan MMG speaker ($550/
pr):
http://www.magnepan.com/model_MMG
B&W 603 speaker (~$1,000/
pr)
http://www.bwspeakers.com/index.cfm/...l%20DM603%20S3
Outlaw Audio RR2150 Receiver (stereo only, but nice, $650):
http://www.outlawaudio.com/products/rr2150.html
If I were going to buy a sub today, I would probably just do an SVS. They just have a great following and such well-respected customer service. All the subs I've ever seen in CC/BB are not gonna cut it for me (I'm sure there are some good ones out there). I heard a Velodyne 18" that was nice, but it was very expensive. If you are so inclined and have the time, energy and patience, I would recommend a DIY sub. There are many around here that will blow away most commercial subs, and for a fraction of the cost.
Oh, you asked if you need anything else. Do you already have a source like a CD or DVD player?
I also noted that you are going to hook up your PC to your system. Will you be using a digital connection? If not, you'll want to consider it, but it can wait for a while. If you're handy with a PC, it won't be difficult.
That's it for now!