The book, "Inner Experience", was compiled post-humously from notes Bataille kept with the intention of putting into book form. Nonetheless, "Inner Experience" is very comprehensive and essential to understanding Bataille's philosophies of base materialism, expenditure, the sacred and the need to transgress the limits of experience.
Recommended reading by Bataille: "Story of the Eye", "Documents", and "Visions of Excess" a collection of essays (edited by Allan Stoeckl). Also, to learn more about Bataille, look up "Against Architecture: The Writings of Georges Bataille", by Dennis Hollier