Published Friday, 15 June 2012
The singer, who performed at the I Will Always Love You hitmaker's funeral in February, has put pen to paper for The Whitney I Knew.
The July release will feature "heart-breaking accounts that led to her ultimate defeat" and will include personal photos from their years of friendship.
Winans isn't the only one to tell all about his relationship with Whitney - the tragic singer's mother, Cissy Houston, is also working on a tome due for release next year.