PraetorianXI
When my spouse and I had the interview and oath on 08/12, we arrived quite a bit early 8.00 am (interviews at 9.45 am and 10.15 am) considering Atlanta traffic. The parking lot had many spots available, but they filled up quickly. We both went in at 9.10 am. The receptionist was on second floor which also houses a huge waiting area (9 rows of 24 chairs placed back to back), Oath Ceremony Hall and many offices of the immigration officials. Many applicants had already brought their relatives with them. There were 12 to 15 IOs calling the applicants by their first names, to make them feel easy. Almost all of them were quite cordial, greeting and asking casual questions like - how are you. Some people, like my spouse, were asked to go to third floor for interview, I am not sure how many IOs are on third floor.
During the interview, if all is good, you will be given a sheet indicating that the process was successful and you will be asked to wait and collect the oath letter. The IO indicates what time will be the oath. We had our oath at 2 pm, the same day. But I also noticed that there was another set of people who had their oath before noon. And, I also overheard an IO informing an applicant that his oath would be at 8 am on a particular day next week. I did not know of the circumstances of that applicant.
I talked to one of the IOs who was with us in the elevator while going for oath. I complimented him for his pleasant gestures, he answered saying that the candidates were already tensed and it was for him to make sure that they feel easy. It was my personal observation that this was the only government office I had ever been to where the employees were courteous and elegant.
Before our oath at 2 pm, all the applicants and only the applicants were asked to sit in the chairs near the ceremony hall. They also announced that the relatives and friends could join the applicants later on. And, we were asked to enter from a door on the far end to make a line and our oath letters were then collected and given laminated number slips. For some of us the certificates were ready and they were asked to verify the info. We all sat in the numbered chairs, per the slip we received. After all the applicants were in, the relatives and friends were asked to sit in the remaining chairs. After the conclusion of the oath process, the new citizens were called according to the number they were given, to receive the naturalization certificates; shaking the hands of the oath administrator and exiting the hall. Though there were no clear instructions on taking photographs, I saw people doing it before, during and after the oath process. We would have to check the certificates. Correcting any mistakes would be easier to do then and there, rather than later. The oath started at 2.30 pm, ended at 2.45 pm.
Now to answer your questions, there is no specific printed oath protocol. You can go back for oath at 2 pm right after your lunch, along with your guests. I assume that you can take two guests (the hall accommodated about 200 guests plus 150 new citizens when I had mine).
Good luck.