Department of Official Language
Official site under the Ministry of home affairs covers the language act, language rules, departmental activities and related resources.
Dictionaries
A collection of freely downloadable dictionaries between several of the principal languages. From IIIT, Hyderabad.
Ethnologue: Languages of the World
List of languages of India and the geographical areas where it is spoken.
Indian Language Alphabet Comparison Page
Eden Golshani's website - charts showing all the letters of the Hindi, Punjabi, Bengali, and Gujarati syllabaries.
Language Journal
Monthly online journal devoted to the study of the languages spoken in the Indian sub-continent.
Maithili Parishad
Promotes the Maithili language and its culture.