The following is a guided exercise. It's intent is to allow you to get out of your own way and let your character tell you about themselves. Simply answer the questions to the best of your ability. Some of the questions will spark more answers. That's good. Just write and move on.
You should write out this information with no structure in mind, simply let the words flow from you. It's intended to allow your mind to be open to whatever inspiration occurs while you think about the character.
Get the information written. Don't edit it. It is not intended to be seen by anyone else. This is information that only the writer of the story needs to know. Put it in a file, single-spaced on about two to three pages in a font about like this (Times-Roman 12 point).
Do this exercise for all of your major characters - the ones who significantly drive your story. Remember, there are no villains, just characters with different points of view about how the world should work.
Keep each 'Character Bio' in a separate file. Keep them all in a separate 'Character Bios' directory where you have your other development files for your story.
Ask yourself these questions about your character and just write down whatever comes to mind. You may be answering some other question, that's good, that's okay. Just let it flow. When you stop typing, just move on to the next question. Good luck!
------- Character Questions -------
Who are their parents? Did they know their parents? Where are their Mom and Dad from? Did they work, what was their profession? Who was your character closest to? Mom or Dad? Did they have any Aunts or Uncles? Were the Aunts or Uncles living with the family? Close to the family? Did they know their grandparents?
When were they born? Are they immigrants? First generation? Second? Did they have brothers or sisters? What were their names? How many of each? Where did your character lie in the family tree? Youngest sibling? Oldest? Middle child? Which sibling was closest to your character? What did they do together?
Did the family have a pet? What was its name? What kind of animal was it? Did it live in the house? Who took care of it? Did they have more than one pet? Who was closest to it? When did it die? Is it still alive? Who takes care of it now? Did it have any good/bad habits? What was your character's relationship with the family pet?
When your character was a child what was their favorite thing to do? How often did they get to do it? Were they artistic? Mathematical? Curious? Conservative? Shy? Were they scared of anything when they were young? If so, did anyone help them with that?
What is their health like? Do they have any allergies? Are they robust? Athletic? Frail? What are their personal habits like? Are they clean? Tidy? Well-groomed? Or not?
What were their favorite clothes? What did they like to eat? Were their family meals or did everyone eat separately?
Who were their friends? Who was their best friend when they were nine years old? Around the age of nine-ten, they learned something valuable from their parent. What was it and what happened? Where did the family live? Did they live in a house, apartment, ranch, condo? What kind of things did the family have? Cars? TVs? Rich? Poor? Was the family close to any other families?
Where did they go to school? Who was their teacher? their favorite teacher? What did they like to study? Were they a voracious reader? Or did they shy away from it? Why? Did they participate in any school functions? Plays? Teams? Clubs?
Around the age of thirteen-fourteen some event occurred in their lives that made them think about what they might do in life. What was that event? How did it effect them? Who else was there?