I recently befriended a beautiful German Shepherd whose owner knows nothing of grooming -- washes him with a hose in the backyard and all.  Not that I know anything about dog grooming either, but I enjoy brushing them!

First thing I learned about German Shepherds:  they have a double coat with hair on top and soft underfur.  Second thing I learned: the underfur sheds rapidly twice a year, spring and fall.  You will definitely need a shedding blade during these times.

Here's a link to an article about how to use a shedding blade:

http://www.ehow.com/how_2057541_brush-dog-shedding-blade.html

Also you need a slicker brush:

Some people swear by the shedding rake:

A friend of mine who trains guide dogs for the blind uses this conditioner on his dogs. Apparently the lavender is calming as well as making them smell nice!

What size Furminator should you use for a German Shepherd?

http://www.germanshepherds.com/forum/basic-care/104141-what-size-furminator.html

Consensus seems to be medium or large:

Buy on Amazon: http://www.amazon.com/FURminator-deShed-Tool-Orange-Short/dp/B0040QW33W

Furminator works great for German Shepherds:

Works great on anything from cats to Siberian Huskies:

I wonder if a Furminator could shave a yak?