Here is a valuable introduction to Theosophy as given in the writings of Madame H.P. Blavatsky and her Adept Teachers.
Mr. Farthing gives an overview of H.P.B.'s teachings on the occult constitution of cosmos and man; the akasha and the astral light; the elements and elementals; death and rebirth; origins of the universe and man; globes, rounds and races; the esoteric side of evolution; spiritualism and psychism; spiritual development; and the inner side of religion.
This book is available in the following editions: