In no particular order:

St. John of Shanghai and San Francisco, A DISCOURSE IN ICONOGRAPHY

Archbishop Gregory, ON ICONOGRAPHY

Atalier Saint-Andre (A community of traditional byzantine iconographers)
ICON PAINTING TECHNIQUE: STEP BY STEP

Iconographer Aidan Hart, ARTICLES & PROGRAMMES

Bp. Auxentios, THE ICONIC AND SYMBOLIC IN ORTHODOX ICONOGRAPHY

THE ORTHODOX CHURCH AND ITS ICONS (extensive site)

A GUIDE TO BYZANTINE ICONS ON THE INTERNET

PROSOPON SCHOOL OF ICONOLOGY

NOVGORODIAN ICON-PAINTING

Archimandrite Kyprian Pyzhov, TOWARDS UNDERSTANDING ORTHODOX ICONOGRAPHY

ICONOFILE: ICONS, ICON PAINTINGS, ICON PAINTNG WORKSHOPS, ICON MATERIALS AND RESOURCES

Reader Daniel, THE LESS-COMMON ICON FAQ

THE ICON FAQ

Blessed Photios Kontoglou (from his book, MYSTICAL FLOWERS, Athens, 1977), THE GREAT WAGER BETWEEN BELIEVERS AND UNBELIEVERS

Blessed Photios Kontoglou, WHAT ORTHODOX ICONOGRAPHY IS

Blessed Photios Kontoglou, ON THE HOLY SPIRIT
and
THE SPIRITUAL WORLD
two articles by Blessed Photios Kontoglou translated by Constantine Cavarnos

Blessed Photios Kontoglou, THE MYSTIC ZION

RUSSIAN ICONOGRAPHY ON THE INTERNET

ICONOGRAPHY REFERENCES: BOOKS