Learn these flags. They, and the corner workers are your best friend.
GREEN FLAG, Course is clear and you can drive at speed.
YELLOW FLAG, Caution on the track, something has happened on the track in front of you. Check your rearview mirror first, then begin to slow down while keeping an eye on what is going on. If the corner worker is "waving" the flag, something serious is wrong and you need to slow the car quickly. NO PASSING during a yellow "caution" flag.
RED FLAG, Something very serious has happened on the track and you need to come to a complete stop on the track. Always check your mirror first as their may be someone directly behind you. If you stop quickly without checking your mirror, you could get rear ended. Try to stop on the track within sight of the next corner worker station so you can see when it is safe to proceed. You should pull over to the side of the track, but stay on pavement when you stop.
BLACK FLAG, There are two ways you will see this flag.
Furreled Flag Pointed at YOU. You have done something wrong and/or there is something wrong with your car. You are being asked to come into the hot pit area to talk to a track official.
Standing or un-furreled black flag waved in the air. ALL drivers are asked to come into the hot pit area in order to recieve further instructions.
PASSING FLAG, When this flag is shown to you, it means there is a faster car behind you and you should let them pass. Remember, this is by point by only and should be done only on a straight. The car behind you should show some patience until a safe pass zone is reached.
MECHANICAL PROBLEM, There is something wrong with your car or another car, proceed into the hot pit to have it checked out. If your car is leaking fluid, pull off line and/or off the track and await assistance.
DEBRIS FLAG, There is debris on the track ahead. It can range from mud / dirt from a previous car going off, to car parts to animals. Use caution while proceeding.
CHECKERED FLAG, The session is over and you should begin your cool down lap. DO NOT immediately slow down as you may have someone directly behind you. You have an entire lap to slow down and cool off your car's system. NO PASSING on the cool down lap.