There are many books on Blavatsky and Theosophy. Below is a very small selection:
Bechhofer Roberts, C. E. (“Ephesian”), The Mysterious Madame: A Life of Madame Blavatsky (London: John Lane The Bodley Head, 1931)
Besant, Annie, H. P. Blavatksy and the Masters of Wisdom (London: Theosophical Publishing Society, 1907)
Cranston, Sylvia, HPB: The Extraordinary Life and Influence of Helena Blavatsky (New York: Putnam, 2003)
Davenport-Hines, Richard, ‘Blavatsky, Helena Petrovna (1831–1891)’, Oxford Dictionary of National Biography, (Oxford University Press, 2004) [http://www.oxforddnb.com/view/article/40930]
Fuller, Jean Overton, Blavatsky and her Teachers (Adyar: Theosophical Publishing House, 1988)
Sinnett, A. P., The Early Days of Theosophy in Europe (London: Theosophical Publishing House, 1922)