Britannica Online
Britannica Online includes the complete encyclopedia, as well as Merriam-Webster's Collegiate Dictionary and the Britannica Book of the Year.
Useful For: Finding background & historical information. Navigation: Type the language of interest into the search bar on the homepage.

Glottolog
Glottolog is a bibliographic database of the world's lesser-known languages, developed and maintained first at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany.
Useful for: Finding a language's family tree and dialects. Navigation: On the homepage, click on "Languages." Identify the column for "Name" and enter the language of interest into the search box.

World Atlas of Language Systems (WALS)
WALS is a large database of structural (phonological, grammatical, lexical) properties of languages gaehred from descriptive materials (such as reference grammars) by a tam of 55 authors.
Useful for: Finding information on a language's lexicon, phonetics, morphosyntax and other components.  Navigation: Click on "Languages" in the navigation bar.  Identify the column for "Name" and enter the language of interest into the search box.

Linguistic Society of America - YouTube Channel
Short videos created by LSA members on a variety of topics concerning language. Videos are intended to fuel interest among language enthusiasts, spark discussion, provide topics and projects for classroom use, and show the many ways in which the work of linguists can contribute to industry, education, and other human endeavors.
Useful for: Learning about syntax, phonetics, or morphology from short videos.  Navigation: Scroll through playlists to find videos of interest. Also, use the search function to identify videos about a language of interest.

Omniglot
Omniglot is an encyclopedia of writing systems and languages. Use it to learn about languages, alphabets, phrases, numbers, and other writing systems. 
Useful for: Finding information about a language's writing system.  Navigation: Click on "Languages" or "Writing Systems" and select the first letter of the language you are researching.