The Dhammapada - 423 Immortal Verses of Wisdom
This small book consists of utterances of the Buddha at various occasions during his life. Even though this book is 2600 years old, many of these pithy verses are as relevant today as they were then.
For example,
"Hatred does not end by hatred; by love alone it ceases. This is an ancient law."(Verse 5)
The first two verses of the Dhammapada summarise an important principle of the Buddha’s teaching - the primacy of the mind and mental volition:
".If one acts with an impure mind, suffering follows him like the cart wheel follows the foot of the ox. .If one acts with a pure mind, happiness follow him like the shadow that never leaves."
The original book is in Pali. The good news is that there are many great English translations available for free online. Google "Dhammapada English translation" and check them out.