I started reading "Hagakure," which was written by the samurai Yamamoto Tsunetomo from 1709 to 1716. I don't agree with everything in the book - some of the things Yamamoto-sama says sound crazy to my modern sensibilities, but there's some powerful quotes in here about bushido. Here's some I liked, with some thoughts of my own -
We all want to live. And in large part we make our logic according to what we like. But not having attained our aim and continuing to live is cowardice. This is a thin dangerous line. To die without gaming one's aim is a dog's death and fanaticism. But there is no shame in this. This is the substance of the Way of the Samurai. If by setting one's heart right every morning and evening, one is able to live as though his body were already dead, he pains freedom in the Way. His whole life will be without blame, and he will succeed in his calling.
The first book of philosophy on bushido I read was the Budoshoshinshu. It had a significant impact on my thinking. One of the largest tenets of bushido is keeping awareness of your death in mind when you live. I try to do this, because it gives you a sense of urgency and importance.
A lot of times the principle is misunderstood - the principle is actually make preparations as if you'll live forever, but live this day that you'd be proud if it was your last. Bushido is not about being reckless. It's about keeping awareness of the end with you, and in doing so, living much more.
It's almost paradoxical - the man who is aware of his death, who relinquishes his claim on life, he lives much more fully. The man who is ignorant of his death does not live as much. Death is not something to be afraid of - it's something to be aware of. Being aware of it makes you more alive, and more effective, and more purposeful.
"The basic difference between an ordinary man and a warrior is that a warrior takes everything as a challenge, while the ordinary man takes everything as either a blessing or a curse."
-- Carlos Castaneda