A bit old school but
Solution Selling is a great read. From the back cover... "When products or services are hard to describe, intangible, have long sell cycles, or are expensive, chances are they're difficult to sell. In situations like this, conventional sales techniques not only don't help, they may in fact hinder success. Solution Selling is a process to take the guesswork out of difficult-to-sell, intangible products and services. It enables sellers to make the way they sell as big an advantage as their product or service. After reading this book, salespeople and sales managers will be able to use a well-tested model that guides them through the process of selling. No more smoke and mirrors, blind luck, or high-pressure selling. Just a step-by-step system that ensures a higher rate of success for salespeople and a higher probability that the buyer's expectations will be met."
"Do. Or do not. There is no try." -Yoda, Jedi Master.