Social networking is huge right now. And I think it's just going to keep getting bigger. Unless you fear people and live under a rock, you can't avoid it.
Everyone is using networking to "get out there". Whether it's for business or pleasure. If you are new to networking, I suggest starting out with facebook. Just avoid the games! But it's very easy to use. And a great way to find old friends. Then maybe you want to move up to twitter. If you are going to use twitter, I suggest using tweetdeck to manage your twitter. I love tweetdeck.
Blogging is a little more time consuming but as you build relationships and attract readers, it's probably my most favorite of all.