How do I check oil levels in an Audi A6?

I want to make sure my car's engine has enough oil for peak performance. Is there a recommended time interval between oil checks or a certain indicator to look for?

First, make sure the car is on level ground and the engine is cool. Locate the oil dipstick near the engine, pull it out and wipe it clean. Reinsert the dipstick and pull it out again. Check to see if the oil level is between the minimum and maximum marks on the dipstick.