The English translation (accompanied with original Arabic text) of the supremely eloquent sermons of the Commander of the Faithful, Imam Ali ibn Abi Talib (peace be upon him). Nahjul Balagha contains 240 sermons given by Imam Ali (a), dealing with a wide variety of topics including our existence, relationship with the Almighty, building a God-fearing personality, and the Imam's (a) reflections upon historical incidents.
The Letters and Sayings of Imam 'Ali can be found here: http://www.al-islam.org/nahjul-balagha-part-2-letters-and-sayings