I recently moved into a new apartment and am working on building a stereo system for a living room that is on the humble side of moderately sized. The room has a bar, and above it are four holes (front facing in a line) cut into the wall to accommodate 4 front facing bookshelf speakers that the previous inhabitant installed. I suppose I am looking to recreate the same setup, but better. On the opposite side of the room is a coat closet that is door less, (old Victorian style) in which I plan to discreetly place a powered subwoofer. Now to the problem. Firstly, I'm on budget, so the idea would be spend the least of amount of money and get obviously, the loudest and best quality sound I possibly can (everyones goal I suppose). Second, I haven't ever divulged into the world of stereo so I have no idea what I'm doing. I have a Sony STR-K502 receiver and want to purchase 4 bookshelf speakers, but I have no idea which speaker specifications would be ideal. The receiver is rated 100 watts per channel (RMS?), 8ohms, and 20-20,000hz. Not entirely sure what Im describing, but the exact specifications can be found here http://www.manualowl.com/m/Sony/STR-K502/Manual/66670?page=46 on pages 46 and 47. I've been trying to look into purchasing speakers but I am deathly afraid of burning out the amp in the receiver, or worse damaging the speakers Im about to invest in. I am unsure if it would be best to purchase speakers rated for 100 watts, or above, or even in that range for that matter. I read that even if thats met correctly, you can still have poor sound quality because of the efficiency. Im pretty confused at this point, any help would be greatly appreciated.Thanks in advance!