Flash cards

jMemorize flash cards for various Chinese characters used in Mandarin, Cantonese, Korean and Japanese.

See also

jMemorize — A Flashcard program used as an aid to memorising facts.

Miscellaneous links

Online lessons and resources

eLanguageSchool.net™ — Chinese, Korean and Japanese.
MIT OpenCourseWare — Chinese and Japanese.
Utah State OpenCourseWare — Chinese.
The Chinese Outpost
Nihongo Resources
thejapanesepage.com
Korean Studies at Sogang

Grammar references

Japanese for the Western Brain
Tae Kim's Japanese guide to Japanese grammar

Exercises

Pinyin Practice

Dictionaries

Chinese/English Dictionary
Thesaurus Linguae Sericae — An Historical and Comparative Encyclopaedia of Chinese Conceptual Schemes.
Jim Breen's WWWJDIC — Japanese-English.
NAVER 사전 — Korean - English - Japanese dictionary with hanja characters.
POPjisyo — A web portal that adds translations to Japanese, Korean, Chinese and English terms in web pages
rikaichan and RikaiXUL — Two plugins for Mozilla Firefox used to look up Japanese words in a web page

Texts

青空文庫　Aozora Bunko — A collection of freely downloadable Japanese texts (out-of-copyright texts etc.)
うわづら文庫 — More of the same, in PDF format
*プロジェクト杉田玄白* — Another collection.

Discussion forums and chats

2ch — An anonymous Japanese message board
IRC@2ch and ReichaNet — Japanese IRC networks (Character set: ISO-2022-JP)
HanIRC — A Korean IRC network. (Character set: Codepage 949 or EUC-KR)

Script reform

カナモジカイ — and 社団法人日本ローマ字会 — Two organisations advocating Japanese script reforms.