People 

Johann Gottfried von Herder 1744–1803 - East Prussia, Königsberg, Riga, Weimar

Encyclopedia Entries

Johann Gottfried von Herder - Wikipedia  
Johann Gottfried von Herder  Stanford Encyclopedia of Philosophy
German Idealism [Internet Encyclopedia of Philosophy]  
Herder, Johann Gottfried von  Encyclopedia.com 
Herder, Johann Gottfried von. The Columbia Encyclopedia

Questions of 

nationalism, pluralism

Reading

Writing available on the net

Modern History Sourcebook: Johann Gottfried von Herder: Materials for the Philosophy of the History of Mankind, 1784  

Johann Gottfried von Herder, Reflections on the Philosophy of the History, selections

Also

Sämmtliche Werke, ed. Bernhard Suphan, 33 vols (Berlin, 1877-1913)
Werke, ed. Martin Bollacher et al., 10 vols (Frankfurt a.M., 1985- )

Roy Pascal, The German Sturm und Drang (Manchester, 1953), ch. 6-8
R.T. Clark, Jr., Herder: His Life and Thought (Berkeley and Los Angeles, 1955)
Eric Blackall, The Emergence of German as a Literary Language 1700-1775 (Cambridge, 1959), ch. 14
Isaiah Berlin, Vico and Herder: Two Studies in the History of Ideas (London, 1976)
Wulf Koepke, Johann Gottfried Herder (Boston, 1987)

Commentaries

Quotations

Brave is the lion tamer, brave is the world subduer, but braver is the one who has subdued himself.

Those that embrace the entire universe with love, for the most part love nothing, but their narrow selves.