Web 2.0 is a concept that is associated with the so-called "second generation internet users." As technology and and the internet evolve, these second generation users now have tools that give them the ability to collaborate and share information online through wikis, blogs, social networking sites, and communication tools.

The three main ideas of Web 2.0 are:

• The Web as a platform - building applications that only exist online
  
• The Democratization of the Web - anybody can create content and share their knowledge and information
• User participation - individual people participate in creating communities on the web and creating networks
  

Overall, Web 2.0 is a general shift in the way the Internet is used.

1) The Basics of Web 2.0
http://computer.howstuffworks.com/web-20.htm
2) Informational Overview and Differences Between 1.0 and 2.0

3) Viral Marketing and Music

4) Video - Social Media in Plain English
http://www.vimeo.com/1083838?pg=embed&sec=1083838