On Nationalism: http://www.gutenberg.org/files/40766/40766-h/40766-h.htm

A sampling of his poems: http://www.poetryfoundation.org/bio/rabindranath-tagore#about

“Tagore and His India,” Amartya Sen (gives an overview of many aspects of his life and work): http://www.nobelprize.org/nobel_prizes/literature/laureates/1913/tagore-article.html

The Home and the World (novel, available in full online): http://www.gutenberg.org/ebooks/7166