Twitter?

So I dove in and signed up at Twitter. I simply wanted to see what it was all about. Ummmm.... I don't get it. Am I supposed to get twitter updates from all 3 people I follow on twitter? Are the tweets (is that what they are called?) supposed to come to my phone? Maybe the 3 people I decided to stalk follow on Twitter haven't tweeted (huh?) lately.. Anyone know how this is supposed to work?