My friends and I were looking at buying some track time. What's ussually required? Just a helmet? Or do I need everything right down to nomex socks?

 

Contact the track and the organization that puts together the event to be certain. Different tracks require different things.

 

Do as Damon said. You don't just rent track time. A club or organization rents out the track and you have to follow the track's and organization's rules.

Typically, since you wouldn't be running in an "advanced" run group, all you will need is a helmet and pants (no shorts), and a tech inspection of your vehicle.