Wow, I really appreciate all of the responses! I got some extra pics that lovinthehd asked for. One of the previous owners of my house owned an A/V store and I think he installed all this stuff. The one speaker says QUARTL on the front, I didn't pull it out of the wall to get more specs on it or pop the covers off the other ones.
The speakers are paired, two in my family room, and two in the dining room. There is a volume control knob in the dining room so I believe I can turn them off when we are listening in the family room.
I haven't really thought of a budget since I didn't have a clue what needed to be done. From the looks of what BMX Trix gave in links, it looks like I may need to spend $100-$200, which I'm OK with.
BMX Trix, if I'm following you. My source (could it by my i-pad?) would connect into the amplifier (through the head-set jack?) and the amplifier would connect to the speaker selector, with speaker wire going from that into a banana plug, which plugs into the wall. Did I come close?
Again, thanks a lot for the help.