Help Me Please with setting up PS3 audio.

Hello everyone,

I'm new to this whole home theater thing and i'm looking for help with playing blu-ray movies. I have a PS3 with all the latest firmware and I have a sony STR-DG710 receiver and 5 speakers and a subwoofer. I have my PS3 going into my receiver via HDMI, which is then output to my Sony BRAVIA via HDMI. What I'm wondering is, what's the best settings to use, in terms of sound, on both my PS3 and receiver while watching Blu-ray movies. I do not believe my receiver supports more than 2 channel uncompressed PCM, but today I was fiddling around with 300 on blu-ray and I set the movie to 5.1 truHD. My receiver showed it was outputting 5.1 sound but it didn't sound like it was really giving me a "surround" sound experience. Basically anything anybody can tell me would be really helpful.

Thanks so much.