I owned a german shepard as a kid. They are medium sized dogs. 
I love dogs. What are german shepards bred for?
German shepherds are working dogs used for herding sheep. 
Are they good hunting companions? 
They are not really used for hunting, but work in other areas sush as guides or search and rescue. 
How long does it take to train them for guiding and searching? 
I have no idea. I would think not a long time because they are known for their trainability and intelligence.
They are a great breed. Are they usually healthy dogs?