There are many theories about the fall of mankind and angels, but from my understanding of the Word of God, Lucifer had to be fallen before mankind or it would have been impossible for him to tempt man with sin. Lucifer was jealous that mankind had authority that he did not have. He was probably one of the mightiest of the angels and held a lot of authority, possibly even the mightiest of angels, but his authority was limited at all times.
Finally a book that addresses creation and is helpful in understanding who we are as human beings. This speaks from a spiritual stand point, but is very helpful in dealing with our spiritual nature. It brings Jesus Christ into the picture and how humanity without Jesus are creatures without purpose.