Wow. I thought this thread was dead and I got a notice that someone responded and I see others have as well.
It is hard to know where to start reading Simone since it depends upon a person's interest. "Waiting for God" is a religious work consisting of her notes, essays, and letters etc. "Gravity and Grace"s more philosophical. "The Need for Roots" is very cultural and describes how France should be rebuilt after Hitler's devestation. Then there is "Lectures on Philosophy" which consists of careful notes by one of her students. There have been recent anthologies which are also good.
She is so far ahead of her time in appreciating the eventual unity of science and religion which will allow science to serve man rather than man becoming a slave to scientific advancement.
Simone Weil: A Life, Random House, 1976, p. 488