Outside of the quality of the screen or the display technology that you choose for your big screen system, your choice of the right home theatre speakers is probably the next most important choice you can make. Why? Because good quality audio combined with the big screen reality of the visual make for the total ultimate big screen experience, and the audio component is not a place where you want to cheap out.
Your surround sound system should be at least Dolby 5.1, and with the latest technologies available, it's not a quantum leap in price to go with a Dolby 7.1 system. A system like this "divides" the sound going to your speakers, so that the high ranges go through these speakers, the mid-ranges go through those other speakers, and the bass is pumped through a footstool-sized sub-woofer. If you wanted to, you could even go the extra mile with your home theatre speakers and look into expanding your audio system with "Bass Shakers" which are attached to your loungers and/or sofas, which is further detailed at this site in the home theatre seating article.
But the key here is the use of surround sound, which uses technology to make it appear that the sound is coming from all around you. Of course, a key component in allowing your home theatre speakers to emulate this is the placement of the speakers. In a typical surround sound system, you have 4 high-range speakers. It is usually recommended that these be hung from the ceiling in the four corners of the room where the big screen system is located. Next you have 1 or 2 mid-range speakers, which I usually put on either side of the big screen, about 1 to 1.5 feet away from the edge. Finally, the sub-woofer is located on the floor next to the big screen itself, ideally elevated off the floor on some kind of decorative platform about 4 to 6 inches. Now all of this said, much of this will of course depend on the makeup and characteristics of the room you have designated to house your big screen and home theatre speakers, but this can be viewed as a general rule of thumb.
If running cables all over is not your idea of a good time, one of your options here is to use a wireless system. This consists of a wireless transmitter near your surround sound amplifer, and a wireless receiver that your home theatre speakers plug in to. Where this type of setup is most useful is in the ceiling-mounted high-range speakers, since it is generally a major pain in the backside to run physical wiring through drywall, into the attic, then drop it again through the ceiling at exactly the right place. If your home carpentry skills are a bit on the lean side, you may wish to consider a wireless setup for those speakers.