If they are willing to learn, ask them if it would be easier if they read about it and just came to you with any questions. For many parents, it is easier to get information from a third party when it comes to the private, intimate lives of their children.

This post gives some excellent advice and an example "coming out" letter that i think is really awesome.
It is originally posted HERE but you need to belong to the site in order to log in and access the writing, which i think is well worth doing. As it's not something i wrote, i'm not comfortable copy-pasting, but it's not too complicated to sign up on Fetlife and there's other benefits of doing so. i recommend it. Anyway, i haven't read it but i've heard/seen it recommended a number of times and the author of the post i linked recommends a book called "When Someone You Love is Kinky" by Dossie Easton and Catherine Liszt, available HERE on Amazon. Unfortunately, EF doesn't seem to carry it. The description of the book on Amazon is: "When Someone You Love Is Kinky to help "non-kinky" folks understand and communicate with their kinky friends, partners, and relatives. Included are guidelines for dealing with the emotional turmoil of the coming-out process; brief and non-threatening descriptions of the commonest kinks (and ideas about why people enjoy them); suggestions for how to talk to your kinky friend or relative in ways that promote good communication; explanation of how kinky people keep themselves safe while exploring diverse sexualities; a glossary of commonly used terminology from the kink communities; a resource guide to help the reader find further information and support."
i think asking them if they would like more information is a good place to start. In general, i assure people i "come out" to that my relationships and practices are safe and consensual and ask them if they would like to know anything else. Let them know you can recommend books or answer their questions as they prefer. i think it's very important to be as open as you can and answer any questions they have as thoroughly and honestly as possible. Hope this helps. Good luck!

I'm gonna second referring to outside sources. One - because your parents probably don't need to know the intimate details of your personal relationship. Two - because hearing things from an educated source is often (though sadly) more believable than hearing it from one person, especially a person who is your child. You can open the door to questions from them, but be prepared for the potential of them asking too much or not understanding when you answer. If they ask and don't understand your answer, try to find a resource that pertains specifically to that question.

I haven't read "When Someone You Love Is Kinky," but if Charletnarouh backs it, I'm gonna go ahead and back it too. She's a smart cookie!

I loved the Fetlife post on "coming out to the parents". It interested me how she kept linking things she learned through BDSM to her everyday life, a wedding speech, self confidence, overcoming fears. This is a wonderful way to use reading material. I agree with Kira in that your parents don't need to know intimate details they just may be interested in "why" you do what you do.

Yep, it helps a lot to have a professional verify that the activities you enjoy are safe and healthy. It can be a bit scary to an outsider

o.o I'm not sure if I would personally. I feel like the more they delve into it the more I would be uncomfortable about it.
I'm lucky in that my parents are in a Don't Ask Don't Tell mindset about my sex life.

The When Someone You Love is Kinky book sounds like a great resource and will probably be your best bet.

If they are willing to learn, I would definitely give them the information