Dear Dana
You can read the below books most of which you can find on Amazon, they should help you out
Crossing the Chasm: Marketing and Selling Disruptive Products to Mainstream Customers by Geoffrey A. Moore and Regis McKenna
Cross-Selling Success: A Rainmaker's Guide to Professional Account Development by Ford Harding
Crossing the Chasm: Marketing and Selling High-Tech Products to Mainstream Customers by Geoffrey A. Moore and Regis McKenna
Selling For Dummies by Tom Hopkins
Cross-Cultural Selling For Dummies by Michael Soon Lee, Ralph R. Roberts and Joe Kraynak