The Why and How-To of Twitter Lists

I'm trying to become more familiar with the capacities of various tools.

Here's a good post on why use Twitter lists. This post not only provides some good reasons for creating lists, but adds detail for use once the list is established (like how to add additional Twitter Users after you've established the list: http://slymarketing.com/how-create-twitter-list

Here's a four minute video tutorial as well: