Hello Herbie, not sure from what you've written at what level your friend has had an amputation, but am assuming it's across his tibia (a below knee amputation). Time to limb fitting is normally around 2 to 3 months depending on speed of patient's healing , however if he wasn't walking that well before, it may well take longer as he will need good balance to sucessfully mobilise.
Good people to contact for support are the Limbless Assoiation, whih is run by amputees for amputees. They will send out an amputee to talk to your friend and give practical advice if he wishes (although this is not a counselling service)
Hope this helps