The Leichtesmaschinengewehr 34/42 was the "default" loadout of the MGXX series; the so called "assault" configuration with a 50 round drum magazine and detachable bipod. Later in the war, someone came up with the brilliant idea of attaching an extra 25 rounds to the wound up ammunition belt, and enlarging the drum; 75 round drum magazines were available on a semi-limited basis.
Contrary to popular belief, you could fire either from the shoulder (
http://youtu.be/O5MAg5feoUQ?t=9m); in both cases the LMG was intended to advance along with the other Grenadiere/Panzergrenadiere/Pioniere/other squadmates, thus being no more than ~50m behind those troops at any given time. In the case of Panzergrenadiere, they had an extra LMG within their 10 man unit and eventually adopted a leapfrogging tactic of an LMG per 5 man section--in such cases, the LMGs became SAWs, per se, with troops being perfectly able to use them as oversized assault rifles at ridiculously close ranges.
As for the MG34/42 auf Lafette; this was a spring-loaded tripod that basically reduced all felt recoil to zilch and enabled the use of the MGXX series out to 1500m+ with little effort; scope attachments were available (and, if used, attached to the tripod) to turn these weapons into pseudo MG-sniper rifles. Crews most often served the weapons from boxes of 250 round belts; the myth that German troops ran around with belts of ammunition festooned across their chests like old-style Mexican bandits is utter horse crap (if ammunition was worn this way and became dirty, the extractor in either case of the MGXX series had an alarming propensity to tear through a cartridge, leaving the forward half of it lodged in the barrel of the MG).
The MGXX series could also be served in the bipod configuration with a two man crew using the box-and-250-round-belt feed method.