PORTALS
Accademia della Crusca Includes Grande dizionario della lingua italiana, Tommaseo, Vocabolario Dantesco, Vocabolario del fiorentino contemporaneo, etc.
Sapera Dizionari di Lingua Italiana "Per lo studio, il lavoro o il tempo libero: trova la definizione e il significato di una parola, oppure cerca un sinonimo o il suo contrario nei nostri dizionari di italiano; trova la definizione e il significato di una parola, traduci un verbo o ascoltane la pronuncia… in nove lingue diverse con il nostro traduttore on-line!."
Treccani Enciclopedia
LANGUAGE DICTIONARIES
Collins Italian Dictionary: Search (Advanced search) in database Credo reference using exact phrase: Collins Italian Dictionay. Credo Reference is a digital reference library that places a world of factual information at your fingertips. Containing a selection from 645 high-quality reference books from the world's leading publishers, Credo Reference is the ideal place to start any research.
Grande Dizionario Italiano Online
ONLI - Osservatorio Neologico della Lingua Italiana Neologisms from Italian newspapers.
OVI - Opera del Vocabolario Italiano (CNR). (For an overview on video click here.)
WordReference Italian Dictionaries
Slangopedia Crowdsourced dictionary of slang.
BILINGUAL DICTIONARIES
Dizionari Garzanti Linguistica English ⇄ Italian; French ⇄ Italian
Oxford Dictionaries online. Fully searchable, completely comprehensive bilingual dictionaries, and unique study materials. It features over 4 million words, phrases, and translations. Includes Arabic, Chinese, French, German, Italian, Russian, and Spanish into and out of English with pronunciation software.
ETYMOLOGICAL AND HISTORICAL DICTIONARIES
TLIO - Tesoro della Lingua Italiana delle Origini Historical dictionary of Italian language
Indo-European Languages Italian Online vocabulary and grammar tutorials.
L'Italiano in famiglia "L'Italiano in famiglia è: un corso multimediale per imparare la lingua italiana." Free online course from the government of city of Brescia: a video sitcom with downloadable episodes, transcripts and exercises.
Radio Arlecchino Italian podcasts from the University of Texas, with transcripts and grammar notes.
Forvo.com Italian Pronunciation Audio clips of native speakers pronouncing 32,000+ words in Italian. This is not a scholarly enterprise but, rather, a representative sampling of the accents and intonations of native italian speakers.
Treccani L'Enciclopedia Italiana
E-Books
Search (Advanced Search) in Quick Search (and limit to Book / ebook) : enciclopedia AND italiana (Retrieves titles going as far back as 1853).