Below are 4 videos showing the basics of Twitter right through to tools that help with managing your Twitter experience.
1) The Ultimate 101 on how Twitter Works
This video provides a very good introduction on what Twitter is and how Twitter works.
2) Getting Started
The basics on using Twitter.
3) Finding People to Follow
How to locate people on Twitter to follow.
4) Tools You can Use with Twitter
This video presents some of the top tools to help make your Twitter experience better.