I am trying to make a lamp using an LED puck light. When I plug my "contraption" into the wall, the LED light goes really bright and then shuts off. Something needs to be tamed! :-)

The Transformer label says:
12V STep Down Electronic Transformer, Class 2, Maxload=60W, Minload=10W, Input=120V 60Hz, Output=12V 10-60W

The LED Light label says:
Input=12V DC, Transformer input=120v-60Hz, Transformer ouput=12V DC 6W Max

The nice guy at Home Depot said it should work. The wiring is set up correctly, but something is too strong! I have attached a picture (I hope).
Can anybody help?

If your led light says transformer input 120v and transformer output 12v DC then it probably already has a built in transformer. The led light uses DC (direct current) power (input=12v dc) your transformer you connected it to probably produces 12v AC.