A great link to using Wave:
http://completewaveguide.com/guide/The_Complete_Guide_to_Google_Wave
Some links about use cases for Wave:
http://mashable.com/2009/11/22/news-media-google-wave/
http://latimesblogs.latimes.com/technology/2009/09/google-wave-collaborative-journalism.html
http://www.christiangrantham.com/2009/11/23/notes-on-media-use-of-google-wave/
http://mashable.com/2009/12/15/surprising-google-wave-uses/?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+Mashable+%28Mashable%29&utm_content=Google+Reader