CK-12 Foundation
Ck 12: Biology: Mollusks
[Free Registration/Login may be required to access all resource tools.] Discusses characteristics of mollusks.
PBS
Pbs: Nature: Encountering Sea Monsters
An extensive amount of information is featured in this PBS site on Cephalopods. Images, videos, books, and web links are just a few of the items that can be found here.