Take some chances. Start by learning the landscape. The Web 2.0 directory, Go2Web20.net, lists nearly 2,500 social networks. You can’t possibly keep track of them all, so pick one and learn about it. Most networks share similar features, so get a sense of why people join them, how they use them and what are the networks’ strengths and weaknesses.
Sign up for Facebook or LinkedIn and connect to some friends who are already there. Spend an hour navigating the site and look at how other people are using it. Social networks aren’t all that complex. The value will be apparent to you pretty quickly.
Spend 15 minutes learning how to use Google Advanced Search. This will save you at least an hour a week, so the TIME investment is well worthwhile. More importantly, understanding the search will help you understand how people find information online. That is a key first step toward understanding the utility of social media.