I agree with Jean on this one. Everyone's body is different. You have to know what gets you to orgasm and then you can tell him what things you like and dislike. Some women have never even had an orgasm! I'm gonna throw a couple D&J resources at you. Some tips for
him on how to get you to orgasm, some
information for you, and some general
intimacy and orgasm info. Then here's a couple videos which may be helpful for you.
Here's one on allowing yourself to have an orgasm.
and...
Why is it so difficult to orgasm with oral sex?
I hope these Dan and Jennifer resources help you.