TONMO

(The Octopus News Magazine Online)
This site is dedicated entirely to cephalopods (octopus, squid, cuttlefish (sepia), and nautilus), their captive care, culture, study, and history. That I have found it is probably the most complete site on this subject. There are articles and forums covering more than the average number of queries. Whether your questions are about aquarium setup and maintenance , breeding, feeding, care sheets, pop culture, marine conservation, fossils etc. chances are you will find your answer here!

Most of the information is free but you can pay a subscription and gain access to their private "Supporters Forums". If you are considering to become an octopus owner and even if you already have some experience with cephalopods this is a site you don't want to miss.

http://www.tonmo.com/