Networking - Who do you Know?

The third platform for Selling (or Dating or anything else) is Networking.
Having trained people in selling for over 8 years, I find this the most difficult thing to train people in, for those who don't get it.
You know people.  The people you know, know people.  When we meet someone, we both bring our networks with us, they sit like some vast forest of knowledge, on our shoulder, as we talk to the other person.
How can I help this person, with who I know, and how can they help me.

They talk about Six Degrees of Separation, but I tell you, in any group of 12 people I've trained, we've been able to get to anyone named in 2 steps!