Obviously there are the CMP boards to learn from
http://forums.thecmp.org/ Also there is Shuff's forum to look at as well. This guy is a WIZARD with restoring and modifying the Garand
http://forum.shuffsparkerizing.com/forum.php Definitely pick up an adjustable gas plug.
Garand Gear makes a good one that drops the port pressure on stock Garands
Another one to look at will be the Schuster DCM Adjustable Gas Plug [I have that one and will be getting the Garand Gear one to test]
That allows you to shoot ultra heavies and hot ammo out of a Garand.
For anyone that thinks that the Garand cannot handle 65,000 psi ammo feel free to look at this link.
Hatcher's Notebook Page 215
Mr Garand wanted to test the strength of his receiver and bolts. He used high pressure cartridges beyond 50,000 at 5K increments. At 120,000 lbs (2.4 times the design limit) the left bolt lug started to crack. He took the cracked bolt and receiver and fired an additional 5,000 regular M2 rounds without any further damage to the weapon. Hatcher states that the Garand is the strongest service rifle period.
And this is also why an adjustable gas plug is recommended
[open it all the way out and it is a single shot. start turning it closed until it cycles your superduper ammo of choice. It also becomes useful if you rebarrel the Garand to 35 Whelen or 9.3x62 and want a semi auto big game rifle.Then there are some other mods you can do.
M14.CA sells some replacements for the rear sight [if you like reflex sights] and scope mounts.
RD mount [I have one, works well but has high cheek weld, my chin rests on my thumb but oh it's FAST
]
MRD : NOTE JPOINT specific (I know, I bought the wrong reflex sight for it]
CASM mount
I have one I can sell you if you want (not a fan of it on my stuff, YMMV of course)
Also you can put a scout rail on it. Ultimak or Amega (google them). An ultimak is on my to-get list
Ultimak on top [lower profile]
Amega on bottom
You can also modify the clip ejection with a Holbrook device
http://m1thumbsaver.com/ 
I have one on my Mini-G and it rocks.
Now let's talk about ammo carriers. Carrying clips can be a real PITA with the wrong gear.
As you can see you can get a two clip mount for the stock.
Olangapo Outfitters makes carriers for ammo
Grab and Go (carries 96 rounds, about $70, worth EVERY penny)
[He also makes the stock side-saddle]
Cartidge belts are an option
$29.95 on Amazon (search and find them)
Another alternate is to use an M203 vest. I got one on ebay for $18 bucks (YMMV) but it will hold 22 en bloc clips of ammo.
There are 24 slots for grenades but two of them will be blank because of the clips and fitting them on the vest.
http://operationeastwind.com/wiki/images/1/12/M79vest.jpg Finally, let's talk en bloc clips.
https://www.wideners.com/itemdetail.cfm?item_id=100000577&dir= Best source and price I have been able to find.
Spend a couple hundred bucks and pick up 200 or so which might be a lifetime supply for most folks.
What's the advantage to an en bloc clip? They NEVER lose tension and you can keep ammo ready to go for decades. Learn en bloc drill for reloading.
Hope all this helps.
Disclosure: No financial stake in any of the above companies.I have more knowledge but that has to do with ammo types and varies depending on what you want to shoot.
Other things we can talk about, Garand variant calibers.
- 35 Whelen
- 9.3x62
- 270 Winchester
- 8mm Mauser
- 7x64 Brenneke
And there there's the 1918 BAR mag fed Garand.
My current personal mad science project is trying to figure out how to make a 30/375 Ruger Garand
[Which does 3200 fps 180gr pill or 3000fps 208gr A-Max .... or maybe even a .223 sabot 55gr/62gr at 4800/4500fps]
And then there are mil-dot scout scope choices, custom stocks, cast boolit options, AP ammo selection [which is federally exempt BTW]
Final thought: A Garand in the right hands is an absolutely BRUTAL weapon compared to an AR.
