Everyone in sales has at least one thing in common: Wanting to be better. To make that happen, you have to become a trusted adviser.

That's the basis of Anthony Iannarino's new book, The Only Sales Guide You'll Ever Need.

People may not see the roles of salesperson and adviser as compatible, but Iannarino articulates in a profound way how you can be both.

The Only Sales Guide You''ll Ever Need is easy to read and very applicable. Iannarino makes the case that when people need results, they want to work with someone they believe can help them make the improvements they need.

When you sell, your prospective client is making a decision--about who they trust, who they want to work with, who can provide them with the right ideas and help them deliver the right results. So if you want to sell better, start by making sure you're the kind of person people turn to for counsel when they need help.

The Only Sales Guide You'll Ever Need discusses nine attributes that give you the right mindset to sell effectively, along with eight skills to accompany that mindset. To give you a taste of his thinking, I've distilled six of the most important attributes he cites:

Caring. All things being equal--and even when all things are unequal--relationships win. That's why your job in sales depends on building relationships. Those relationships, in turn, are built on caring, empathizing with your clients and truly helping them. Iannarino says that if you want your clients to trust you, they first have to feel that you care about them. This other-orientation is the foundation of being someone people want to do business with.

Resourcefulness. Resourceful salespeople can accomplish things that seem impossible because they approach problems with a different mindset than their less resourceful counterparts. They put their creativity to work on behalf of their companies, their clients and themselves. If your clients could produce the results they need without you, they would have already done so. They need your ideas, your creativity and your imagination. Now more than ever, resourcefulness is the linchpin of value creation.

Accountability. Taking accountability for superior outcomes transforms you, in your client's eyes, from a salesperson to a value-creating trusted adviser. In the past, you might have gotten away with selling something and quickly disappearing when things went wrong. Not anymore. Today, when you sell you own the outcome.

Business acumen. To become a trusted adviser, you must be able to dispense excellent, sound advice. To do so requires an understanding of general business principles and the ability to apply them thoughtfully. Iannarino calls business acumen the new sales acumen, arguing that you can no longer create any real value by describing your product's features and benefits--you have to provide the reasons your clients need to change and the ideas that will allow them to propel their businesses forward.

Change management. We live in a world where more and more decisions are made by consensus. More people are engaged in the process, and we need everyone to come along with us as we make change. Or, at least, we need them to stand down and allow the change to happen. Iannarino says that consensus building, like business acumen, is a critical skill. Helping different groups of people come together for a shared purpose is difficult and messy, and the ability to do so separates the best from the rest.

Leadership. What makes you a leader is your decision to take responsibility and to act on that decision, no matter your position on the organizational chart. You become a leader simply by behaving like a leader, by owning the responsibility for the outcome you sell. Iannarino finds that most salespeople don't think of themselves as leaders--but they are required to lead their own team, and sometimes their client's team, in producing results.

Don't stop with this small sample. The entire book is one that can change your entire outlook--and your entire career. Even those who aren't in sales will find a lot of great ideas about how people work together to make things happen.