Relationships and Resources (The Music Industry)

Today the Middle Men will be discussing the purpose of relationships and building resources from these relationships.  Every person you meet on a positive level in the music industry has some sort of resource to provide for someone you know or yourself. 

What makes relationships valuable? What types of attributes after building a relationship help you identify what resource this person possess?  When dealing with someone you know that has additional resources, what are the ethics of obtaining the resources from the person you know?  Is that person obligated to provide you with the resource when you know they have it?  What are some ways to build your own database of resources without ruining your relationships?