Well, first off pretty much every floor standing speaker will be able to connect to your Onkyo. Speakers don't come with speaker wire (usually) so you will need to buy the wire to connect the the speakers to your receiver. Also, consider buying banana connectors to put on the ends of the speaker wire to make future connections easier. Don't over-pay for speaker wire either. Goto monoprice.com and buy the wire and connectors there and save some money.
As for good floor-standing speakrs in the $500-$1000 range (assuming you just want a pair):
PSB Image T55 Towers (http://www.psbspeakers.com/products/Image-Series/Image-T55-Tower)
Elemental Designs A6-6T6 Towers (good value) (http://www.edesignaudio.com/product_info.php?cPath=2_42&products_id=96)
AV123 towers in your price range (their website is not loading correctly for me).
Also, check out avsforum.com and goto the speaker section. There you will find lots of info on customer reviews for speakers that I didn't mention.
Which 2 way floor floor standing speaker in the range of $500 to $1000 would be compatible with Onkyo TX-SR606 ?