trying to do the sound thing without a clue

[krazeyeyez]

im just starting to look into getting a sound system set up for home theatre....but i have no idea where to begin. last time i bought a stereo left AND right chanels were the new thing

my real question is whats the differences between 5.1, 6.1 and 7.1 setups and how noticable is the difference? i would love to have great sound but im not an audiophile and i want affordable without cheaping out and getting something i'll regret, but i also want to future proof this setup. if some one could point me in the right direction of key features i should be paying attention too in my research i would greatly appreciate it.

p.s.
just got my tv and blu at the start of Dec. and i am still feeling the wow factor....gotta love blu.