How clean should a weapon be before I take it into the arms room?

Weapons should be cleaned in accordance with current guidelines. When I was an armorer I refused to take a weapon back until it was clean.

http://www.thefirearmblog.com/blog/2016/08/01/cleaning-the-m4-carbine-army-approved-process/

When you are in charge, take charge!

Cleaning a weapon isn't exactly hard to do, We drew weapons each duty day and cleaned them ourselves before turning them in. I had already checked My weapon to make sure it was clean and would pass inspection by the Armorer. In the long run if I didn't take care of My own weapon i put Myself at risk, it had to be fully operational if I needed to use it. Also make sure You put some light oil on the moving parts to insure they move freely as they should. Keep Your hands off the metal parts, the moisture in Your hands can cause rust. Its not complicated and in everyone's best interest to take care of this equipment and everyone should be picky about the weapon being clean and serviceable.