Background: I work for a small company that provides medical education
opportunities to healthcare professionals.  We are compensated by
pharmaceutical companies to assist them in marketing their products. 
Typically, they only do business with 'preferred vendors'.  Every
company has a different process for becoming a preferred vendor.

Question:  How does a company become a 'preferred vendor' for
GlaxoSmithKline (located in Research Triangle Park, North Carolina)? 
Specifically, what are the detailed steps that must be taken?  What
are the details of the process to include timelines, required
information, and key points of contact?

Significant tip will be included based on depth of detail regarding this process.

Thank you.