The Graf Zeppelin was put on water on 8 December 1938, in the same year Germans started building second carrier, a twin to Graf Z. - the Peter Strasser (don't know what happened with it later, probably never built more than 10% of it). Graf Zeppelin in 1940 was almost ready (90%)! The main problems were catapults and aerofinishers. The problem was solved, but decision was to stop building the ship.
42 planes were to base at Graf Z. - 2 squadrons of Bf 109T and one of Fi 167 (later Ju 87C). The artillery was really heavy as for an aircraft carrier. 16x150mm (they were put into project by mistake - original project included only 8 guns, but someone have mistaken, putting 8 guns on one board, which automatically doubled its number), 12x105mm and noumerous 37mm 20mm.
In 1942 when workers came back on board of Graf Z., the Kriegsmarine decided to rebuilt a bulk of heavy cruiser Seydlitz in Konigsberg. It was supposed to be equipped with 18 planes. Never finished of course.