Salespeople are not the only ones involved in sales. The truth is that whether we are in marketing or not, each one of us has something to sell; from goods and services to our personal brand. Consequently, how well we practice and master the art of selling determines how far we go in our chosen paths, and how successful we become in life.
I wrote an article about five books written to help do exactly that. Read it here:
http://connectnigeria.com/articles/2013/03/12/great-reads-top-5-books-for-marketers-and-salespeople/