Thank you everyone for your help and advice. I just got back from the Buttonwillow event, and what a blast it has been. I ended up going out for 6 sessions of 15-20 minutes each. By the end of the day, both my car and I had all the driving we could take for a day!
Braking, as predicted by many of the posters here, was a problem. The pads started to lose some of their bite on the second or third session. They were still usable with increased pedal pressure. But then on the last session the brake fluid faded (good call AKA) and the pedal went completely to the floor! (Does anyone on pit road have a spare pair of pants?)
Another problem was overheating. This is the first time I've ever witnessed the temperature gauge read anything higher than 3 notches up! It didn't become a problem until some run groups got combined and the car didn't get enough cool down time before the next run.
We ran clockwise on the track for the entire day, and by the end, my left front tire was close to complete destruction. I also underestimated fuel usage (got about 8-10 mpg) and so had to buy at the track ($2.79/gal).
All in all, it was a lot of fun, and a wonderful learning experience. I found myself often over eager in the turns and carry too much speed on entry. I learned quickly to calm down after several dramatic sideways excursions. To think, it would just simply be insane to learn such consequences of over driving the car on anything other than on a race track!
WOOT!!