Handbooks and dictionaries can be better starting points than article databases or even the library catalog. Use literary handbooks to find out about literary periods, terminology, definitions, and to put an author's life and work in context. Note that some of these excellent reference books are not online.
This comprehensive dictionary is an excellent first-stop resource. It describes an author's life and work in the context of his/her times. Covers many major German-speaking authors.
Oxford Art Online
A superb art history resource