Hello,
As you've read from the site, the tournament is just a part of a whole series of events taking place in Pistoia throughout the entire month of July. The Joust of the Bear takes place every 25th of July in Pistoia's Piazza del Duomo.
Starting at 10am, there will be a historical parade through the center, ending at the Piazza del Duomo, with a mass taking place in honor of St. Jacob at 11am in the main cathedral.
The actual Joust takes place in the evening and is preceded by the arrival and parade of the Giostra's knights (starting at 7:45pm) and the actual Giostra dell'Orso begins at 9:30pm, all at the Piazza del Duomo.
(In addition, on the 22th and 23rd of July at 9:30pm the knights will be practicing in the piazza del Duomo for the Joust, if you'd like to see the extra show. The evening prior, on July 24, at 10:30pm there will be a series of fireworks at the Campo di volo).
As the event is a highlight of the summer, you can expect there to be lots of people and for there to be some difficulty in finding parking as you would at any event, particularly if you arrive in the evening just for the Giostra. However, you can plan to arrive earlier in the day and take advantage to see a bit of Pistoia. Otherwise, I'd suggest taking the train from Florence and maybe staying for the night. The ride takes from 40-50 minutes, and if you choose to return to Florence, the last train leaves around 23,00 from Pistoia.
You can reach Pistoia:
BY CAR: from Florence - A11 Motorway towards Pisa, km. 35
BY TRAIN: Daily connections from and to Florence.
BY BUS: Daily connections on the bus-line Firenze-Viareggio by Autolinee Lazzi.
For other events taking place during July (concerts and shows), see
Comune di Pistoia
Useful links -
train schedules -
Ferrovie dello Stato
bus schedules -
http://www.lazzi.it/eng/activenews.asp
other details on pistoia from the city -
http://www.comune.pistoia.it/index_eng.html
accommodation listings -
Strutture ricettive in Provincia di Pistoia (italian)
I hope the information I have given you is helpful, let me know if I can help in any particular way further. Hope you have a wonderful time in Florence and Pistoia.