Your Author-Preneur biography should only be a nice statement of your writing credentials. The information in this section should describe your special education, skills, publications, activities, memberships, etc., that attribute to your writing experience and skillset, demonstrating that you are involved in the industry and continue to learn and grow as an author and as a professional. Because this is a bio for a factual work, it should also tell the reader who you are, why you are qualified to write this book, why you are the right person to tell this story, or share this knowledge.
Not just humor, but the overall tone of your application essay is remarkably important. It's also difficult to get right. When you are asked to write about your accomplishments, those 750 words on how great you are can make you sound like a braggart. Be careful to balance your pride in your achievements with humility and generosity towards others. You also want to avoid sounding like a whiner -- use your essay to show off your skills, not to explain the injustices that lead to your low math score or failure to graduate #1 in your class.