my dogs fear

Question
Hello, I have two dogs; a mother (Troy) and her son (Hektor). Mother is the mixture of German Shepherd and Turkish Kangal. Troy is very strong and brave dog, but her son is afraid of everything, especially when we spare him from his mother. He is 6 years old now, and we do not know what to do to make him not afraid of humans, other animals. When he is with his mother, he barks at everything, everyone. When he is alone, he goes to the unreachable point of his shack and hides. Hope you can help us with this!

Answer
It sounds as though he may not have met enough people and other dogs while he was still a very young puppy.  Sadly, the socialization time for dogs is very limited, so he may always be fearful.  However, there is a procedure called "desensitization and counter-conditioning" that could help him be a bit more comfortable with the things he's most fearful of.  It involves Pavlovian conditioning - creating an association between the thing he fears and something pleasant happening for him.  
You probably need a veterinarian and a trainer's help, but if no trainer is available to you, there are some resources to help familiarize yourself with fear in dogs and how to deal with a globally fearful dog:
http://www.youtube.com/watch?v=zf9ZnAmvu8U&feature=related
www.fearfuldogs.com