Dictionnaires:

AllWords.com
multilingual dictionary
Answers.com -
French version of Answer.com
Dico éco - RecyNet
over 20 000 words and expressions related to environment
Dictionnaire anglais bilingue
bilingual dictionary
Dictionnaire de l'informatique et d'internet
computer dictionary
Dictionnaire des Couleurs
colour dictionary
Dictionnaire des Rimes
rime dictionary
Le dictionnaire multifonctions - TV5.org -
my first stop when I need a dictionary
Francparler.com
definition and origin of French expressions
Le Grand Dictionnaire -
bilingual dictionary (my favourite)
HarryDico
Harry Potter dictionaries
The Internet Picture Dictionary: French
basic picture dictionary with interactive activities
Le Jargon Français
French and English computer terms
Les-dictionnaires.com
Directory of best online dictionaries
Lexiques d'Orthonet -
search words with approximate spelling - great tool
Lexiques officiels des sports Olympiques
olympic sports lexicon
Mon Emploi
description of 1500 trades and professions
Ortograf
when you can't spell the word you're looking for
Racines Latines
find out about the latin roots of the words
Le Signet-Informatique -
French and English computer terms
Synonymes
French Thesaurus
Synonymes.com -
Seems to be the best French Thesaurus
Vocabulaire d'Internet (OQLF)
vocabulary related to the internet
WordReference -
French-English dictionary

Grammaires, ...

L'assemblée des homonymes
Cartoon, exercises and activities not to confuse homophone
BOF - Bréviaire d'orthographe française
French spelling
Leconjugueur.com -
conjugate verbs (includes a tool for entering French accents)
Le Devoir Conjugal
conjugate verbs
Le Français au Micro
misuse of some French expressions
Grammaire Interactive
French grammar
Une grammaire ... pour le primaire
French grammar for primary students
La langue de chez nous
good section in "Grammaire et orthographe" for lists of vocabulary per theme
Manuels de grammaire en ligne
French Grammar
orthographe-recommandee
official recommendations for spelling changes
Orangoo -
free online spell checker (click on "change", select "Français")
"Le Patron" - Aide à la rédaction -
online electronic French grammar checker
Règles de ponctuation et de typographie
French punctuation rules
Le Site de l'Orthographe
more than 200 simple spelling rules
Tex's French Grammar
French grammar in English
verb2verbe
conjugate verbs in French of English - test your knowledge
WebVerbix
conjugate verbs in over 100 languages

Traduction:

Atlas sémantique - Dictionnaire de synonymes bilingues
sort of a French-English thesaurus
Babel Fish
translate text, website
Reverso
translate text, website with accents from drop down menu

Encyclopédies:

L'aménagement linguistique dans le monde
states and linguistic policies from around the world
aneki.com (E)
quickly find facts and figures for over 190 countries
Cyberflag
find facts while exploring world flags
Earth Calendar - Celebrate every day! (E)
every day is a celebration!
eNature - Nature and Wildlife Field Guides (E)
search online field guides - excellent advanced search
Encarta
Microsoft encyclopedia in French
Encyclopédi@ ERPI
encyclopedia associated with Google
Encyclopédie Canadienne
Canadian encyclopedia
L'Encyclopédie de médecine et de santé
site that makes medical knowledge accessible to all
Ethnologue, French in the World
Statistics about the language
HowStuffWorks (E)
learn how everything works
InfoVisual
learn by way of image with thematic pages
Population Data
French world facts
Wikipedia, l’encyclopédie libre
community encyclopedia
The World Factbook (E) -
The CIA World Factbook

Atlas:

3DFlags.com
flags of the world
Atlas du monde
historical, economic andpolitical data
Atlas historique
history with maps
ANCL - L'atlas national du Canada en ligne
the National Atlas of Canada Online
La Centrale des Nations
over 30 indicators per country
The List - Graphic Map's World Atlas (E)
list of continents, countries, dependencies, islands, territories, lakes, rivers, seas, oceans, mountains, and the highest, lowest, biggest, smallest, tallest, deepest, oldest, youngest, richest, poorest places on planet earth, and more!
Longitudes et latitudes des villes et villages du monde
latitude and longitude of more than 2 million cities
Map Clipart (E)
Graphic Maps and World Atlas - clip art for students, publications and web sites

Citations:

Ab nihilo (latin)
latin quotations
Les Citations du Monde
quotations of the world

Dictionnaires de la Langue des Signes:

ASL Browser (E)
look up video of thousands of ASL signs
HandSpeak (E)
a sign language dictionary online
LSF Lexique des termes de spécialité en Langue des Signes Française
more than 500 French signs