The website team met today. We finished renaming links and now will actively start the card sorting process. We're going to go with an online solution and are currently deciding between WebSort and OptimalSort
Meanwhile, I am going to immerse myself in Drupal by installing it on a remotely hosted site and working with it, reading tons of documentation and books, and becoming an active member of the Drupal Community.
Once the card sorting exercises have been finished and I'm pretty confident with Drupal, I will take the results and alter my site map accordingly. Then I will populate a Drupal prototype with the site map and barely populated pages. The public will have access to the prototype and will probably even be able to comment on it.
Then its on to the next phase, Design, Content Population, and Usability Studies...