German armed forces on land were actually a mix of Heer (army), Waffen-SS, and Luftwaffe troops. The Heer was the background, with a long heritage. The Waffen-SS (Schutzstaffel) was the military arm of the Nazi party, and had primacy of recruiting. The SS was often considered an elite force, and was supposed to be made up of the strongest and most politically enthusiastic soldiers. The Luftwaffe was the air force, but also provided divisions of soldiers to fight on the ground, notably (but not limited to) the Fallschirmjäger, paratroopers.
The players ought to be regular Heer troops. Fallschirmjager and Luftwaffe ground troops saw very limited use in the Soviet Union, and the SS was not active around Sevastopol, where the campaign starts.
A quick primer for those not familiar with the terminology. This describes German army practice in 1942; there are some changes across nations and time, although the terminology and hierarchy remains constant.
A rifle squad was the basic fighting unit, and the smallest independent unit in this period. A German squad was supposed to be made up of 10 men, but as was true with every army, often went into combat severely under strength. An unteroffizier (Sergeant, in US terminology) was supposed to command.
A platoon was made up of four rifle squads and a single light mortar section and commanded by a Lieutenant or increasingly by a Feldwebel (staff sergeant)
A company included three rifle platoons and an anti-tank rifle section. It was commanded by a Hauptmann (captain), or occasionally an Oberfeldwebel (Master Sergeant)
A battalion was comprised of three rifle companies and one machine-gun company, commanded by a Major or Oberstleutnant (Lieutenant Colonel).
A regiment was made up of three battalions and anti-tank and light artillery assets, commanded by an Oberst (Colonel).
A division had three regiments and an artillery regiment. Divisions and above were commanded by successive ranks of General.
Divisions could be combined into corps or armies. Armies included both corps and independent divisions. Finally, series of Armies made up an army group, the typical strategic unit. For example, it was the 6th Army which fought at Stalingrad, and three Army Groups (North, Middle, South) launched the invasion of the Soviet Union along three strategic axes.
Although there are many resources online, this page provides a wealth of basic information on the infantry experience in the second world war.