Successful networking has one hard and fast rule. If you know nothing about networking, if you can't remember all the ideas of how to meet people, if you are awkward in real life and can only network online, if you can never think of something clever to say -- whatever your handicap -- it doesn't matter. You need to remember only one thing:
Networking is about what you give, not what you get.
I was fortunate enough to that at one of the first pure networking events I attended, and it's the bottom-line truth. You can immediately identify the person who mingles at a networking event and is focused on the next person they will meet rather than the person they are talking to right now. Everyone knows someone who only calls when they need something. Those people aren't going to get much cooperation when they call on you for a favor.
Actually, I was just joking with a colleague about someone we know who only stays in touch if he thinks he can get something from the relationship. We agreed that we love the guy and we laughed it, rather than being annoyed. After some thought, I realized he can get away with it because he will always, but always, take your call if you need him. So he won't call just to gab; but he also doesn't expect you to, and he will always be on the lookout for how he can help you.
Actually, a few years back, someone told me about an interesting study which showed that women tended to focus their networking on higher-ups, rather than on peers or people lower on the ladder than they are, and this limited their ability to leverage the network. One reason is that a network is an investment, not a loan. The other reason is that you really don't know who will help you, and you don't know who will be promoted tomorrow. Everyone is worth investing in, regardless of their ability to help you.
I actually heard a talk-show host who, while interviewing Tom Hanks, told him he had started out as an assistant in the office, and he remembers bringing Tom some coffee. Tom Hank's immediate reaction was "Please tell me I was nice to you."
That's networking. Whenever you meet someone, whether it be F2F or virtually, the first thing in your mind should be "how could I help this person?". It could be on a personal or professional level, or just telling him where there's a good restaurant nearby. You have something to contribute; don't be stingy.