CLIA is the Cruise Lines International Association. It certifies travel agents as Accredited or Master Cruise Counselors. This page provides access to lots of unbiased profiles of Cruise Lines and ships. Sample Menus for most cruise lines can be found here. Shore Excursion information for a large number of different destinations can be found on this page.
Shipboard activities are many and varied.
Candy Brock has a sample list of a day's activities. Cruise Brochures , many of them free, can be ordered from this commercial site. Seacruise Reviews is a good page for unbiased cruise reviews, many from followers of the rec.travel.cruises message board. Cruise Opinion Database is a numerical database of Cruise Ship Ratings. If you prefer quick numbers to long evaluations, go to this site.