If you are driving in, get in line by 6. (Chicago is on Central Time.) When you get into the drill hall you will see some signs with the division numbers on them. You best for photography, is to be up about half way. We were all the way up to the top of the main bleachers, and I wish I had been a little lower. But be sure to sit in front of the sign with your sailors division number. If you have seat cushions, I suggest you take them. Those bleachers get awful hard after a while.
Also keep in mind that pictures or video are not allowed outside the drill hall while on base. Once you are out the gate, you're good. You could lose all of your pictures if caught. Trust me, I found out the hard way back in 2008.