Ethnologue offers rich data for each language of the world, from populations to maps, dialects, usage, and more. Look at statistics for a given country, region, or the world or plug the raw data into your own analysis tools to tease out exactly what you need.
LLBA is the main article index for linguistics. The database covers all aspects of the study of language including phonetics, phonology, morphology, syntax and semantics with abstracts of journal articles from over 1,500 journals. Also provides abstracts of books, book chapters, and dissertations.