This is directed to authors--and probably newer ones to the profession. I'm sure those of you who have been around for awhile know all this.
Every author should have a bio ready to submit when attending a conference or a con, being a guest on a blog, and for the back or the inside of your latest book. (This goes for a good photograph too.)
In fact, you might want more than one bio ready.
Some bios should be more business like and stick to your credits as an author, what professional organizations you belong to, and perhaps a hint of where you live.
Other bios, especially those for a guest post on a blog, might be a more personal and mention things about our family, hobbies, and/or pets.
When I have a guest on my blog it's certainly helpful if the author's photo as a .jpg (and the cover of the book), the bio and links come along with the post.
Having a bio (more than one depending upon where it's going to appear) is part of being a professional writer.