1996 Ford Taurus WON'T START !

Hello, I have a taurus thats giving me problems. The other day we drove the car to the park for a picnic, so we started out the day and the car started fine. Drove to the local store and stopped for some supplies, shut the car off. Come back out and car started fine, so we drove to my buddies house to grab their family to head onward to the park. We got to my buddies house shut the car off went inside and helped them get ready to go. We came back out, car started fine so we hopped in our car they got in theirs and made our way. We got to the park and shut the car off, we were at the park probably 4 hours had our family picnic and left. "Car started fine" as we were driving down the hill the car felt fine no issues, and as we were coming to a stop sign (#3 of 3 on the drive down the hill) all of a sudden I lost power and the car dies on me when I come to a complete stop at the sign. I shut off radio and told family not to panic. I tried to start the car, all I get is a single click when turning the key. I got the car pushed off the side of the road, and immediatly calle dmy buddy who had just walked in the door to his house. He came back out to help me, and we tried different things for the next 3 hours on the side of the road. Unhooked the battery and even let it sit for 30 mins. THIS CAR WON'T START ! So we have gotten the car back to my house bumper to bumper and here it sits. I have tested battery voltage. 12.00volts, the positive battery wire heats up on me and the starter does not turn over. I am very frustrated and dont know ehich way to turn next with all the electronics on this car. I cannot afford a mechanic so I am doing things myself. Please give me some guidence.