It's hard to say whether it's brave men throwing their fates to skill and chance ... or just a bunch of drunks tormenting animals. Probably somewhere in between.
After the fighting bulls reach the plaza del toros and are secured, the organizers will release smaller bulls into the arena. But these aren't even bulls, they're cows, and their horns have been taped or dulled. This part, this part is nothing more than a bunch of drunks tormenting animals.
Focus on the enceirro. Get your run right. There are countless photogs along the course, and they'll post their photos for purchase later that day ... so don't try to take your own photos along the course.
It's a 24/7 party that shuts down the normal operation of a good chunk of the town. Most livers of mortal men can't handle the full seven days of the event, and there's no shame in dialing it back a bit.
Oh, and getting your photo with the Hemingway statue will be a surprise disappointment, if its still cluttered with event trailers and the such. A skilled photog can save the photo. The average monkey on the street will disappoint. But with digital, at least you'll know right away if the photo sucks.