If you have received a Google Wave invite only to login and stare blankly at the screen and say ‘ok, what now’ get yourself over to view the excellent online Google Wave guide. This is the most comprehensive guide to gWave that I have seen so far.
And if you are too impatient to read through the wealth of information there, here is a quick tip: In the search box in the upper left replace the text ‘in:inbox’ with ‘with:public’. This will show you a listing of all of the current waves that are marked as public. You can further search by including additional tags after public (for example: ‘with:public cincinnati’ for cincinnati related public waves).