Best Practices/Methods: Promotion of Business

All,

Been around for 35 year and started 9 corps, but always been the technologist and referred the marketing to others.

Recently with emergence of SEO, SEM and Social Networking the whole marketing dynamic has changed.

I want to ask an possibly document this question:

In these changing and emerging markets and methods, what are the best practices in marketing today?

Thanks!

TBNK