For those whose coursework and research focus on linguistics, Vanderbilt has many key reference titles, in print and online. A sampling of them is given below.
World’s Major Languages. 3rd ed. (New York: Routledge, 2018)
(Print only: P371 .W6 2018 – Peabody Library reference)
Contains detailed information on the history, phonology, morphology, syntax, and other aspects of the world’s major languages.
World Atlas of Language Structures. (Oxford: Oxford UP, 2005)
This unique resource collects information on the phonological, grammatical, and lexical properties of the world’s languages and, in 142 detailed maps, shows the geographical distribution of speakers who use languages and dialects with these properties. See the companion website also.
Cambridge Handbook of Linguistic Anthropology. (Cambridge: Cambridge UP, 2014)
(Print only: P35 .C25 2014 – Central Library stacks)
Oxford Handbook of Developmental Linguistics. (Oxford, UK: Oxford UP, 2016)
(Print only: P118 .O935 2016—Peabody Library stacks)
Oxford Handbook of Universal Grammar. (Oxford, UK: Oxford UP, 2017)
(Print only: P201 .O946 2017 – Peabody Library stacks)
Oxford Handbook of Computational Linguistics. (Oxford, UK: Oxford UP, 2003)
(Print only: P98 .O95 2003 – Central Library stacks)
Phonetic Symbol Guide. (Chicago: University of Chicago Press, 1996)
(Print only: P226 .P85 1996 -- Peabody Library reference)
Handbook of the International Phonetic Association: A Guide to the Use of the International Phonetic Alphabet. (Cambridge: Cambridge UP, 1999)
(Print only: P227 .I52 1999 -- Central Library stacks)
There are lots of linguistic data to be found online. The following are a few major sites. To suggest additions to this list, see my comment box.
Provides access for searching several large databases, including Corpus of Contemporary American English
EF Cambridge Open Language Database
Searchable database of spoken and written language of adult ESL learners
English Lexicon Project
“[A]ffords access to a large set of lexical characteristics, along with behavioral data from visual lexical decision and naming studies” from six universities
Google Books Ngram Viewer
Searches the enormous Google Books corpus to determine the relative frequency of words or phrases through the past two centuries
Max Planck Institute for Psycholinguistics
Many databases herein
MLA Language Map
Uses data from 2006-2010 to show the location of speakers of thirty languages within United States
Enormous, engrossing database showing semantic and lexical relationships between words