When I started getting into octos a few years ago, I bought a 30 gallon tank with the intention of setting it up for the octo. Somehow it ended up with clownfish. This was a very good thing because now I know that a) 30 is too small for a bimac and b) I had a year of saltwater experience before setting up a 75 gallon bimac tank.
Having said that, I think it is possible for someone without much experience to keep an octo successfully if they're conscientious, understand the responsibility and perhaps have a little bit of an analytic mind. You see dozens of impatient pre-teens who spending their parents' money and brushing aside most of the research.
The web is a surprisingly good resource if you're willing to take everything with a grain of salt. You should also be able to find some good books on saltwater aquarium water chemistry (everything else in books tends to be out of date or a highly personal opinion).
As for sites, check these out:
Use the search features before you ask specific questions. Most have already been asked. You can spend all night reading the tonmo archives and learn more answers than you ever thought you had questions about. I'm sure others will suggest other sites, too.
On every subject you read about, ie, cycling the tank, look at instructions from a number of different sources and compare them. Always evaluate the source of the information. Most of the posts you'll see on reefcentral's ceph forum are full of crap (ex. it's just in a 10 gallon tank for now, the 30 is coming next week. It won't need to cycle because I'm using water from another aquarium!). Keep in mind most/all of the people at your local fish store don't know anything about octopus either, even if they stock them.
The important thing is to understand what every component in the system is (What is nitrite? Why do I use carbonate sand? How can rock be live and how on earth can it cost so much?) before you start building your setup. Also understand that this will probably cost you well over a thousand dollars and an octopus' captive lifespan is in months, not years.