Q: What tire pressure do I run? 
A: Good Question!

 In the race compound tires, (anything with an SC), Before you go out on the track (cold), they should be around 29 psi in the front and around 25 psi in the rear.
If you have tire warmers, you can set the tire pressure hot, which is a way better way of doing it. After an hour on the warmers, should be 32 psi front and 28 psi rear.
Whether you are using warmers or not, right after you come off the track and the tires are hot, the front should be between 32-33 psi and the rear should be between 28-30 psi.

Diablo Corsa 3s should be set cold at 32 psi front and 30 psi rear.
Rain Tires and Wets should be set at 32 psi front and rear cold.

If they are low: add pressure, if they are high: remove pressure.

Q: What are the compounds and how do I know which compounds go with the SC #s? 
A: Well, it's quite simple really, the lower the number the softer the tire: 0 being the softest and 3 or 4 being the hardest. As far as compounding goes a 0 would be an extra supersoft, 1 a supersoft, 2 a soft, 3 a medium, and 4 a hard. There are also color codes used, White = 0, Blue = 1, Green = 2, Yellow = 3, and Orange = 4. 

Q: What compounds should I use? 
A: It really depends on what purpose the tire is going to be used for, street, sprint race, endurance race, track days etc. The most popular compounds are, by far, SC1's and SC2's. Below is an idea of what is a suitable tire for some of the west coast tracks: