Isiberian makes some good points.
I genearlly alos do not like HTIB systems. It makes it extremely hard to upgrade without full replacement ( and all audiophiles upgrade when the get the itch and the $$
)
The fronts are absolutely the most important spend 1/2 of your $ on them.
There are lots of good fronts, audition the ones you like that fit your budget.
For movies and TV (dialog coes from center speaker) get a matching center to maintain timbre ( seamless front sound) spend 1/6 of your $.
After fronts and center a good sub is next in importance for bass and low frequencies. Get a good sub spend 1/6-1/3 $. A cheap sub sounds bad. SVS and Hsu are good brands. There are good inexpensive subs such as the Dayton SUB-120 HT from Parts Express for $155.
http://www.partexpress.com/pe/showdetl.cfm?Partnumber=300-635
And last for enhancement/fill think about adding surrounds. If you want louder turn up the gain. spend you remining 1/6 or less $.
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If you are starting out and want a good low cost system ( I would stick with 5.1 I agree with Isberian 7.1 is a waste). Look at bookshelf speakers such a Cambridge Audio S30 or Mordaunt Shorts. The Dayton sub is a good inexpensive start. When you upgrade, then the fornts can become your surrounds
Audioholics Online Store sells a very good starting AVR the Yamaha RX-V365 Surround Receiver for $229.95
http://store.audioholics.com/product/2360/66343/yamaha-rx-v365-surround-receiver
Good Luck!
NJ