Amsterdam Tourism & Convention Board
Canal boats for hire.
http://www.amsterdamtourist.nl/en/home/search/transport/boat+rental.aspx

Canal.nl
Explore Amsterdam using a canal bike or a hop-on, hop-off canal bus.
http://www.canal.nl/uk/

Holland.com
Contains general information about canal cruises in Amsterdam.
http://www2.holland.com/us/index.html?page=http://www2.holland.
com/us/amsterdam/attractions/gracht.html