I have done a little more digging and found referenced in the "Hand-Book for Active Service; Containing Practical Instructions in Campaign Duties for the use of Volunteers", Chapter VII. Guard and Guard Mounting by Egbert L. Viele published in NY by D. Van Nostrand, 1861. This is a Northern publication but I believe others similiar publications both North and South will have additional information. I do not know of a publication that would have information like the three General Orders that are listed below from the modern Army Field Manual (FM) 22-6. Guard Duty.
1. I will guard everything within the limits of my post and quit my post only when properly relieved.
2. I will obey my special orders and perform all my duties in a military manner.
3. I will report violations of my special orders, emergencies, and anything not covered in my instructions to the Commander of the Relief.
...or the unwritten unoffical 4th General Order: I will guard my post from flank to flank and take no crap from any rank.
If you read a volume of soldier's accounts you will see how the modern day General Orders evolved and you will also see that although they may not have been published, soldiers general adheared to the principles.
I hope this helps.
Gerald D. Hodge, Jr.
War Between the States Historian
Historian: 39th Georgia Volunteer Infantry Regiment