Written well, bios make a targeted, persuasive argument about what to think about someone without being unsupported self-praise or too salesy. Sometimes I write bios from scratch for people. When that's the case, I keep the finished bio to one page or less and write the biography in the third person. Mostly though I have to take disparate bios and rework them to create consistency in length, tone and voice.
In either case, I always ask people to make sure their bios contain these essential elements:
Description of their business in brief.
Not only do website visitors want to know what people do, they also want to know who people have worked with. I ask them to include a sentence or two about their business niche (or niches) as well as the types of clients they serve. Sometimes a modified version of their 30-second elevator pitch works perfectly.
A list of any awards they have received.
Names of the organizations, clubs, or associations to which they belong.
Any professional certifications and designations they hold.
I have them make sure they write out their names in full, rather than use abbreviations. Not everyone might know what an acronym stands for and in a different discipline, it might represent something else. If they no longer hold a particular designation, but it has played a major role in who they are and what they do, I make a reference to it. I don't include abbreviations of college degrees, like MBAs as it looks unprofessional. The only exception to this would be for a Ph.D. designation.
Places they've been published.
Self-published or not, their works add to their level of professionalism and credibility. If they've written any articles, books, e-courses or e-books I showcase them.
Have they been a guest on talk radio or television? Were they or their business featured or even mentioned in a newspaper article? If so, I include it. Again, these types of "mentions" add to their credibility and presence.
A sentence or two at the end about their personal passions and their relationship to the organization.
This may or not make it into the final bio, depending on the organization, but it's always useful to have on hand.
One professional, and one casual (which should still be a headshot and be a good picture). I ask them to make sure the headshots are as hi-res as possible.
Am I missing anything?