First off I am not a scientist but I have read a lot about cloning because I find it fascinating. And I am not an expert on stem cell research but then again at this point I don't think anyone is. Anyway this is my take on it all. Feel free to correct me if you think I am off.
Embryonic stem cell research is NOT cloning. Cloning is a process where one being is replicated as itself using it's own DNA. It does not use a sperm. DNA from the being is placed in an egg from that being and electrically stimulated to cause it to split and begin the process of growth.(Except in the case of an extinct being like the Woolly Mammoth. In that case if DNA is successfully obtained from its remains it would be implanted into an elephant and the baby would be a hybrid),
Embryonic stem cells are fertilized with an egg and a sperm and grown for a short period of time and then coaxed into different organ cell lines that are then allowed to grow so they can hopefully be inserted into a sick person's organ and multiply as healthy cells. Hopefully the healthy cells take over control. In a spinal cord injury these cells are used because they can reproduce and grow the injured cord so as to hopefully allow it to heal the disconnect.
Adult stem cells can only be used for the organ that they are taken from, embryonic stem cells can grow into any type of organ. Embryonic stem cells don't get old like adult stem cells do or as least as fast.
http://www.biofact.com/cloning/human.html