If you don't know something, you ask someone who does know. If you don't know whom to ask, you ask someone who might know whom to ask. That's the point of social networking.
The thing to remember is to go for quality rather than quantity. (Although you should have a few people in your social network who went for quantity instead and have a lot of contacts.) What quality should we be looking out for?
Look for people who can say 'yes'. Look for people who can get things done - and who can do so in an efficient and trustworthy manner.
Help others, grant favors. An honest and courteous attitude ensures that you too can ask for favors from persons you haven't proven yourself to beforehand.
As always, use your judgment in regard to social networking too. Being deceived a single time is generally a small price to pay to find out what kind of person you are dealing with - just make sure you are not continually taken advantage of.