Can anyone suggest a good sales & marketing book for selling a service?

I own a small business and work out of my home. I sell a service, not a product and would like some good reading material on sales and marketing.

Anything from Stephen Schiffman, Zig Zigler, OG Mandigo (The Greatest Salesman in the World), Selling to VITO, Susanne Roane (How to Work a Room) and Dale Carnegie (How to win friends and influence people).

PS the process is the same, regardless of what you sell. Spend more time on discovering/revealing the need than closing. Schiffman will spell this out for you.