Help with setup

Ok. Im a super novice so don't laugh at me. I have the following speakers:

polk side speaker
proseries 1000 definitive center
prosub 800 subwoofer definitive
yamaha receiver (7.1) about 5 yrs old
sont ps3 (for my blue rays)
At&t Uverse DVR

I need to know what components I need to get the best possible sound from these speakers/equipment (as best quality digital sound possible)

Any help would be greatly appreciated. Just tell me what I need to buy to make the sound hook up the best. Thanks!