Introduction to the Middle Way — Chandrakirti's Madhyamakavatara
This work presents an adventure into the heart of Buddhist wisdom through the Madhyamika, or Middle Way - teachings, which are designed to take the ordinary intellect to the limit of its powers and then show that there is more.
Buddhism for Beginners — by Thubten Chodron
This user’s guide to Buddhist basics takes the most commonly asked questions - beginning with "What is the essence of the Buddha's teachings?" - and provides simple answers in plain English. This is an ideal first book on the subject for anyone, but it's also a wonderful resource for seasoned students.