Where do I start with a home theater system?

First, if you have not already done this, is to connect your present stereo to
your audio video output. Good two channel can beat mediocre surround
sound.

Option two. As you may not really want to go whole hog. I would purchase
a inexpensive new or used surround sound receiver. Adding a decent
center channel and subwoofer. Using your present primary speakers for
front and back speakers as possible.

Option three. Buying one of those pseudo sound bars which have a built in
sub, or out-broad sub. Some of these type units don't sound too bad and
have the advantage of easy integration into your room.

Option four. Quality low powered receiver, new or used, they cost less
money. And purchase of 5.1 speaker system. Some great deals can be had
from good speaker makers. Will be maintaining two systems however.

As always let your ears and wallet lead the way. Nothing easier than
spending someone else's money. Have fun, it's only TV.

By the by. Good luck with the plasma. They still look best to my eyes.

Personally, if you have never wanted to do full-on home theater...and you love 2 channel...i would take Glen's first option. its what we do at home.

Superb 2 channel plus a kick ass sub or 2...and you'll get (imho) 85% of most hometheater...until you start building serious custom hometheater with propery time delays, sound barriers, etc...

...if you want to check if sub really kicks ars, you should get it close to sub and feel if one gettin' kicked when it's on.