Here is an excerpt from an essay I just finished on German rearmament:
Under the Treaty of Versailles, the Reichswehr (the German military prior to the Nazi party
assuming power) was severely limited in its power. The army was restricted to 100,000 men,
including only 4,000 officers. Similarly, the navy was limited 15,000 men, and all members
of both forces had to be volunteers. The navy was banned from possessing submarines and
limited to six warships, while the use of an air force was forbidden. The types and amount of weapons the Reichswehr was permitted to possess were described in meticulous detail, with only light arms and field guns allowed; heavy guns and armour were banned. All possible measures were taken to prevent Germany from rebuilding her military with speed or secrecy; The general staff were officially dissolved; production of each munition was limited to a single factory; all but four military schools were closed and the Reichswehr was not allowed to keep soldiers’ records after they left the military, so that ex-soldiers could not be rapidly recalled at the onset of war.5
And citation 5. reads: John Gooch, Armies in Europe (London: Routledge & Kegan Paul, 1980), 196; Warren Bayard Morris Jr., The Weimar Republic and Nazi Germany (Nelson-Hall, 1982), 240-241; Herbert Rosinski, The German Army (Frederick A. Praeger, 1966), 211–212, 221.
Also; it isn't entirely true that heavy guns were banned: There were a few fixed-position heavy guns allowed at Königsberg, though no where else.
Other books that discuss the Treaty of Versailles:
Adam Tooze, The Wages of Destruction: The Making and Breaking of the Nazi Economy (London:
Allen Lane, 2006). (Limited to its economic impact and how it effected the later Nazi economy)
Götz Aly, Hitler’s beneficiaries: Plunder, Racial War, and the Nazi Welfare State (New York: Metropolitan Books, 2007) (Similar economic disucssion as above but with a very different interpretation.)
Otto Nathan, The Nazi Economic System: Germany’s mobilization for war (Duke University Press, 1944) (Older book, most of the facts on the treaty should be right, though the interpretation of the effects may be outdated)
W. M. Knight-Patterson, Germany: from Defeat to Conquest: 1913–1933 (George Allen / Unwin Ltd., 1945). (Again, facts but possibly not interpretation)
Also it should be noted that I said 200,000 men in the German army above; The Reichswehr had plans to expand to 200,000 men in defiance of the treaty before Hitler took power, but couldn't get the money together, so only small expansions were made before the Nazis took over. They did do a fair bit of stuff in defiance of the treaty though.