Many debut authors don't know what to put in their bio. That's understandable! In fact, I recently met a debut novelist whose bio at the end of her book said this:
This is Lucy's first novel. She lives in San Francisco.
When I asked Lucy about it, she laughed and said she knew it wasn't much, but she had no idea what else to write. She hadn't won any awards. She'd never written anything before. She hadn't even majored in English!
Not to worry.
If you're in the same boat as Lucy, here are my two cents on the issue: I don't think what you write in your bio is as important as how you write it.
For "how you write it" I mean two things:
If you're putting yourself out there as a professional writer, be sure that's reflected in your bio. (For example, I've lost track of how many indie authors refer to themselves as Authors in their bios.)
If your book is positioned as a comedy, make your bio funny! If your bio makes me laugh, I'm much more likely to want to read your stuff. If your book is a mystery, write something mysterious about yourself. (I could never write a mystery, so I'm not sure what I would do in this case, but you get my point.)
If you have life experience that relates directly to the content of your book (e.g. you were a police office for 20 years and the book is about a detective, of if you're a nurse or a doctor and the novel is about life in a hospital), of course include that information in your bio. For the rest of us who simply make things up for our stories, I truly believe that elements 1 and 2 are enough. So stop stressing and get writing!