Hopefully it won't take too long to figure it out. You've gotten some pretty specific suggestions for equipment here, so that should get you there pretty quickly. If you have any questions, let us know.
Most, if not all, of the things that I recommended can be purchased at Radio Shack. The only thing that they might not have is the 3.5mm switch box. I'm not sure about Walmart. You can certainly check out radioshack.com to see what is available at your local stores, or just stop by there.