Go here and download the free .pdf manuals. Note the need for the provided UN & PW.
http://www.biggerhammer.net/manuals/
Buy a copy of Hatcher's Book of the Garand and Hatcher's Notebook too. About $30 each at your local gun shop or Amazon. The former has a troubleshooting chapter and the whole history of the rifle's developement. The latter is a 'must read' for any shooter, but especially anybody new to U.S. military rifles. Chapters about ammo, headspace and more about the developement of the rifle and its rivals. Both are a good read too.
The rifle is designed to be field stripped with no tools except for a cartridge. The gas cylinder nut doesn't need to come out for regular cleaning.
The rifle was designed to use .30 M1 ammo(with its 174.5 grain bullet at 2640fps), not .30 M2(with its 152 grain bullet at 2800fps. M2 started at 2700fps, but got bumped up, in 1940, to match the ballistics of the .30 AP ammo). When you get that far, think 150, 165, hunting bullets and 168 or 175 grain match bullets(Sierra Matchkings) using IMR4895, IMR4064 or Varget. The best hunting accuracy comes with 165 grain hunting bullets with IMR4064. Target loads use the same powder but 168 grain bullets out to 600 yards. The 175's past there. 150's are for general shooting, but a 165 is more versatile.
The latest Hornady manual has a chapter for M1 Rifle specific loads. Hornady makes a 150 grain HPBT FMJ and a 168 grain A-Max. Sierra makes 150 grain MatchKings too. Cheap they ain't though.