Forget your old DVD player. The DVD player that the hometheater system comes with will give you better picture and sound than the one you want to connect. For the best possible picture, use HDMI (if you have an HDTV), component video cables (red, blue and green) or if you don’t have either of those, use S-video (black and looks like the same thing you computer mouse uses). The red, white and yellow jacks are the lowest picture quality with the lowest sound quality.

For you speakers, read the back of the new speakers and find out how many watts they are rated for. They look at the back of the old speakers and see if they are the same or higher. If they are any lower in wattage, connecting them to your receiver will blow them out. The whole idea with new home theater systems is to give you everything you need to have great sound with as little work as possible.

Chances are you’ll be happier if you just plug in everything that comes in the box than if you try and piece it together yourself. If you would rather stick to what you already have, write down the wattage of your speakers and just buy a receiver seperately at the store. They run about $200 to $300, but make sure the one you buy won’t blow out your speakers.

Not really, you still need a suround sound receiver/amplifier.
The amp sends the proper signals to each speaker.