I'm a novice piecing together my first HT and am in desperate need of guidance!

Pieces have so far:

1. TV (Sony KDL-52XBR4)
2. Speakers (5 Mirage NANOSATs)

I'm in the market for a receiver and subwoofer and have a remaining budget of about $1000 remaining. I've looked at a few receivers - Harman Kardon, Onkyo and Yamaha but am having a difficult time differentiating. I'm even more clueless on subwoofers.

All help, advice and suggestions are greatly appreciated.

Thanks!