Here are a few things I like to take with me to the track
Shoe Polish- for writing dial in on windows
Helmet- can't race without it
Tire Gauge- very important
Timing Light- got to have it
Towels- just wait till you need one and don't have any
Rags- same as towels
Garden Water Sprayer- I use it to spray the motor down if needed, I bought mine at Sears for like $9
Ice Cooler- nice to have to put food and drinks in
Video Camera- execellant tuning device
Someone to tape your car with the camera- very handy to have
Magazine or book- time between rounds can be boring, bring something to do
Pen and Paper- these are like the towels, just wait till you need them...
Jack and Jack Stands- I usually don't bring these, but they can be very useful
Bring Some Friends- having someone to talk to is always good
Sun Protection- sunglasses, sun tan lotion, that kind of stuff
Oil and Transmission Fluid- you never know when your gonna need it
Tools- only bring what you think your gonna need or have room for. If you have the space, bring the whole tool box. I usually only bring the basics like a few wrenches and a socket set, a spark plug socket, some screwdrivers, and maybe a magnetic pick-up tool