Get there about 15 min before the oath ceremony.
Go through the security area (you and your guests together).
All the guests need is drivers lincese.
You wait in the lobbby just past the security area.
There is funny guy there that makes sure you are in the right place.
After about 30 minutes (yes, 30 min after oath time on your paper), they ask you to line up.
They send all the guests to ceremony room (they sit in the back rows).
They make sure you have answered all the questions on the back of the oath letter. (answer NO to all the questions). If you answer Yes to any of them, they pull you out and you have to explain it.
Then one by one you go to the window.
show your oath letter and green card. They take both of them at the window.
then they check off your name on some list.
After that they take you to the Ceremony room.
You sit on a chair in one of the first 7 rows in the front.
Watch a video, slideshow, speech.
Take the oath with everyone facing US flag.
Then one by one they call people's name.
Once your name is called you go up front and they give you your citizenship certificate.
Friends and family can take picture during ceremony (even with Flash).
then they show some more videos.
After about 1 hour, the whole thing is done.
From the time I arrived (20min before scheduled time) until the whole thing was over, it took little over 2 hours.
After ceremony is over, you can go talk to the Passport folks who have a table setup in lobby to answer your questions.
I expected them to video tape the ceremony and I could buy a video tape or CD for $$. but they didn't. they didn't even have an official photographer. So that's why they are so relaxed with people taking picture during the whole program using flash.
Good luck.