:ma:
It is excellent to find a good biography to learn more about the prophet Muhammad. In addition, the collection of Hadith from Bukhari and Muslim are considered among the most reliable testimony about Muhammad, so you may want to look into collections of hadith as well. I have a book called "The Wisdom of the Prophet" by Thomas Cleary, which is a nice collection of hadith selected from Bukhari.
As stated in the introduction of the book:
"Authentic accounts of the Prophet reveal him as a pragmatic man, down to earth yet brilliantly spiritual, stern in matters of right yet compassionate and clement, rich in dignity yet extremely modest and humble; a poignant story-teller gifted with a keen sense of humor, a manly and valorous warrier who was most kind and gentle with women and children; a diligent worker, a conscientious family man, a good neighbor, a just king."
The more and more I learn about this great role model, and try to follow his example, the more my heart is touched. I hope you will find the same.