Mom This is How Twitter Works
The best (to the point) tutorial I've come across that explains this social media avenue...Twitter can be a very confusing place whether you've been using the social media site for some time or you're brand new to Twitter. It's challenging enough to decide how to say what you want to say using just 140 characters, but figuring out all the @'s and who sees what is even harder. This handy guide called, aptly enough, "Mom This is How Twitter Works" tells you step by step, with plenty of illustrations, how to use Twitter.
Source: Gizmo's