One of the best reasons to help others is so that you will realize that it is enjoyable to help others. You may think that you are inconveniencing someone to ask for a 30-minute informational interview. No, in fact you might really enjoy it. You may help people who are unable to help you and vice versa. The point is to be a part of a cooperative community and everyone benefits.
Most people think of networking events where tons of people swap business cards.
These are usually not very effective because most people are not sure what to do with the cards they pick up. The best place to start is with your own address book. Family, friends, etc. Family members are great to practice on, and they usually know you very well. You would be surprised how many contacts your close friends and family have if you just sit down and ask them.