Thanks!! I know I was a nervous wreck last year when I registered for this race, so anything you want to know, just ask!
Also, to speak to the faster runners at the back comment, you can always move back a corral. Some of those in our group were assigned corral A with time proof around 2:20-2:30, but moved back to C to start with friends.
It seemed to settle out around mile 2 or so... faster folks moved on ahead. I recommmend moving as far to the front of your corral as you can, if you are in a later corral and are worried about the sweepers.
I know that some faster runners might be irritated by this recommendation, but honestly, if you are really a faster/veteran runner and want to PR this course or not start with slowbies like me

laughing

, your proof of time should be putting you way past Corral E.
You can always show proof of time on race packet pickup day and get your corral moved up. They even have computers on-site and the race services people can look it up for you.
This is so far the only half I have done, but it seemed to be a very supportive race. Our 2 race-veteran friends said that it is a beginner-friendly course, as well.
FWIW (and this feels a bit like posting my weight!!), I had no proof of time and estimated my finish time at 3:30, and was in corral D (of A-E). I finished in 3:11 and was 8765 out of 11,359 finishers. The last place finished finished in 4:03 and the clock time was 4:11. It looks like that was about the cutoff for the sweepers... a good 40 min from 6AM.
Since I posted that, I guess I can be brave enought to say that I was 220 lbs when I started training for this race and had never really run/walked before, except a few charity 5Ks. I supposed I was in moderate-to-not-so-good shape. I was 195 when I did the race.