Write your bio in first person for query letters, third person for most other purposes including proposals, book jackets, article bylines.
Make it professional but you also need to convey personality and writing style. Don’t try too hard to be funny, but include something that makes you seem like a real person.
What gives you credibility? What makes you interesting? What helps people connect with you? (When you’re on Twitter, Facebook or your blog, what kinds of posts seem to get the most comments?) These are things you can briefly include.
If your book centers on something specific—the Civil War, for example—are you a member of a Civil War society? Have you published any articles in historical journals? Include that.
Try not to include too much “resumé” type information–education, job history, etc. because it tends to be boring. Only include what’s relevant to the book you’re pitching.
As you write a bio, consider carefully the purpose of the bio – who is the audience? Is it agents and editors? Is it your blog readers? Tailor it to this audience.
How to write a bio if you have no publishing credits:
- If you’re a member of a writers’ organization such as SCBWI, ACFW or ASJA, you can mention it.
- You can mention if you’re a member of critique group or if you have a degree in literature or writing.
- Don’t say something like “I’ve been writing stories since I was two years old.”
- Keep it short and sweet, i.e. “Jane Smith is a fifth grade teacher in Bellingham, Washington, and is a member of ACFW.”
A bio for a query letter:
- For FICTION, if you’re unpublished, it should be one to two sentences—about 50 words or fewer.
- For NON-FICTION, it should be longer, enough sentences to establish your credits, credentials, and/or platform in the subject matter of your book.
Some tips for the process of writing a bio:
- Read author bios in a couple dozen different books. Note what you like and don’t like.
- Make a list of things you MIGHT want to say about yourself. Try to list 20 to 30 things—don’t self-edit, because you don’t want to leave anything out. Later you can choose the best elements to include.
- Write two or three bios of different lengths so that you have them ready when you need them.
- Trade author bios with a writer friend and help each other make them interesting.
Source: Rachelle Gardner: Literary Agent, Editor & Publishing Coach http://www.rachellegardner.com/how-to-write-a-terrific-author-bio/