Different peoples need different introduction. If anyone want a light weight smooth reading I'll recommend Wilson. Although it is easy read, it'll take you even to the matroids. If anyone want a proof based intro, research paper like, then West is the best choice. Diestel, Harary are to some extent for intermediate/advanced readers. Some encyclopedic resources are Handbook of Graph Theory, Handbook of Discrete and Combinatorial Mathematics, and are easy read. By any means bondy-murty ranks first, assumed that readers are not below average.