Here are some useful links. In fact, there are too many to cover everything here. For the moment, I will limit them to the ones cited below.
There are many useful programs, bits and pieces of information, etc., including Jim Breen’s free EDICT dictionary.
Blue Sky Library (in Japanese)
You will find many copy-right free Japanese novels for your reading pleasure.
Genki Resource Library (in Japanese)
Genki is the textbook we use at Bishop’s University. You will find quite a few materials developed for the textbook here.
The most comprehensive source of teaching jobs. This is a free electronic newsletter and it lists English teaching (and other English language-related) positions at conversation schools, universities, jukus, colleges, public schools and companies all across Japan.
The mother lode of Japan Job Info!