If you live near a big city, you might see if they have a "high class" sex shop that has seminars. Some stores like Good Vibrations, Toys in Babeland, etc. have seminars where they will get a group of people together and provide a seminar and then allow you after normal store hours to shop in their store with a discount coupon.
I attended a seminar in how to perform oral sex on a woman at Babeland once. It was interesting and educational. It was taught by a lesbian and a straight guy. The Lesbian gave the most interesting insights in how to pleasure a woman orally. I have heard that Babeland when it does the oral sex for men course has both a gay guy and a straight woman teach the course.
There are also some videos out there by Sinclair Institute and Nina Hartley (porn star and former nurse). Then again there are tons of books, go to Amazon.com or Barnes & Nobel dot com for books on th3e subject.
Good luck and your husband is a lucky guy.
>43 years of marriage--My wife and I are now closer than we have been in decades. I believe that my SSM is over.