For general sex and relationships I recommend Hot and Unbothered. Its from a sex therapist and it talks about how to find and ask about the sex that you actually want. Its got great advice for anyone about how to think about your relationship and even has some exercises and worksheet (like a Yes, No & Maybe checklist).

For Kink the top two books are The New Topping Book and The New Bottoming Book which gives overview for topping and bottoming. They both start with some examples of what goals or feeling you might want to achieve. Some of their examples are Empathy, Creativity, Bigness, Nurturing, Control, innocence, Lust, Power etc. It then gives some practical advice about how to start with experimenting and how to ask about getting what you want. Its a great way to see what is out there even if you aren’t interested in kink.

The real reason you should check them out is for communication skills for on-going enthusiastic consent. If you see how someone asks to be hog tied with a ball gag in their mouth and whipped silly its easy to ask for anything else. Same with safety both emotional and physical. The most interesting part is how right after giving detailed instructions on how to whip someone is how choking is never safe. Its interesting to see what can be safe and what cannot be.