Cunnilingus is the art of making love to a vagina with your mouth and tongue. Any woman you learn to do it right for will appreciate you all the more for it. What applies to the penis applies to the vulva-- every one is different, requiring a different touch to make its owner happy.
How fast should I go?
This is not an attack. Do not go after the clitoris like a fireman attacking a fire. Quite often at first, the clitoris is far too sensitive for direct stimulation. Lick around it, stimulating the hood, teasing her inner labia, tasting her. Take your time and listen to her. Some women make noise, and some do not. It will be a while before you learn exactly what your lover prefers as far as oral sex is concerned.Some women may like additional stimulation-- a finger or two into the vagina, or perhaps even the anus. She may want your hands to reach up and play with her breasts, or she may want your fingers to hold her labia apart so that your tongue can get at her vulva more directly.
What about taste ?
If the taste or smell bothers you or is a concern, ask her to wash first. Most people who enjoy cunnilingus agree that a clean vagina is a good, if acquired, taste.As a woman nears her climax, she may want more direct stimulation. In general, fast, rhythmic stimulation is most effective at causing climax-- but there shouldn't be a rush to get there. Take your time and learn to appreciate what you can do for her.