il Palio di Siena

http://www.ilpalio.org/schedules_of_the_palio.htm

About a week prior. Generally the City issues the City Ordnance with the schedule of works about a month prior to the event. For example for the last Palio of August 16, 2012. The city issued the Ord. on July 20 mandating that the scaffolding had to go up starting on August 8 and be completely in place by August 10. The City commission was scheduled to test the safety of all installations on August 11, 2012 at 9am. The entire structures would be up throughout the event and everything had to be removed by the next day (Aug. 17).
For the July 2, 2013 event, I would expect similar timings. I don't know what days you are referring to. Big crowds are generally only on the day of the race ("Carriera"), i.e. July 2. It's very crowded but you can try to enter the inside ring up to minutes before the start. You enter from the city hall side. The senesi go crazy during the race, so expect to see very little unless you pay premium money to sit on some of the stands. There is a bit pushing and shoving to try to get the best places where you can see something, but overall not too much stampeding. I don't remember that anybody died during a stampede at the Palio. Any other day, there aren't really crowds comparable to the day of the race. As soon as the race is over go to the district ("contrada") of the winning horse. There will be major celebrations with wine coming out of city fountains. On the way there you'll go through other (losing) districts where people are literally crying as if their mother had died that day.

Bob/Roberto....thanks for the great information. Awesome. We are excited about attending il Palio. It looks amazing. Thanks again so very much!