Free/$20 a month
In the great world of kink education, KinkAcademy.com is a top resource! The site offers a lot of blog posts and videos for free. For a $20 a month subscription, you can access all the site’s content.
The site brings together the top experts in each area of kink to offer a huge range of information: from beginner to advanced expert level. You can learn anything from how to safely and enjoyably engage in pick-up play at a dungeon to how to throw a single tail whip.
I have used this site as a reference when I am exploring a new aspect of kink or want to deepen my understanding of a specific aspect of kink. Recently, I used them to learn the basics of throwing a singletail whip. While not the same as having hands-on insturction, this was a great place to start! And… it is guarenteed top quality information about kinks (unlike googling it or trusting whatever YouTube serves up for free).
All the experts on the site teach. Most of them charge significantly more than $20 for a single class, let alone access to all this content. For anyone of any level exploring kink and BDSM, a subscription is well worth the investment!
Full Disclosure: I have a few pieces on KinkAcademy. I do not recieve any royalties or funds from click-throughs or purchased subscriptions.