For marketing strategies, a great book series that I love are the Guerilla Marketing series. They have lots of great ideas. The number one way is to network because people buy from people they like and know - relationships are what sell. You can write articles and speak for organizations in your industry as well to get the word out that you are an expert (if this is an area you excel in).
Pam Newman is a Certified Management Accountant, author and Certified QuickBooks ProAdvisor for Financial and Point-of-Sale software. She is also president of RPPC, Inc., which provides customized business development services.