Unique Author Box for Unique Authors.

Hello Friends,

I am using the latest version of WordPress and now my question is I have a default author box installed, which displays the author info at the end of the post. But I too get many guest posts from various authors, and I am not able to publish their author bio as there is a default author bio, if I want to display their author bio then I am forced to create a user account on their name and use the author bio.

Creating user names for all authors might be a difficult task. Can any one you suggest me is there any plugin through which helps me to select the author bio before publishing the post or allow me to add customer author info before publishing the post.