The German Soldiers lucky enough to be captured by the Western Allies were kept in prisoner of war camps located in the Western countries. They were treated pretty well and besides some isolated incidents were treated well (much better than the Germans treated their POWs). Now, the 2 million German soldiers who were unlucky enough to fall into Soviet hands, were mistreated, starved, and used for forced labour in prison camps. After the war the regular soldiers held captive by the western allies were released relatively quickly. The ones held by the Soviets were released slowly and many were left in labour camps, official Soviet records show that 356,687 of the 2 million German POWs in Soviet captivity died. The last bunch of German soldiers were not released until 1955.

Since Germany was under allied occupation until 1949, there was no military meaning most regular soldiers simply went back to German and tried to find their families or rebuild. Some high ranking Germans were recruited by both the Western allies and the Soviets to help rebuild the German army, but these were usually high ranking important officers and not regular foot soldiers. The allies also used German POWs to help rebuild shattered areas in the immediate post war era. For example German troops were used to clear out minefields, dismantle fortifications,etc.

Source:

Third Reich Series by: Richard Evans

I've heard that a lot of combat soldiers joined the French Foreign Legion, and ended up fighting and dying in Vietnam. It would be ineteresting to find out more about that if anyone has anythign more to say about it.