The following is an excerpt from a book titled Budo Secrets (order a copy here). Not only is this important for a martial artist, but it is something we can all benefit from in our daily lives.
1. Never Lie
2. Never forget to be grateful to one's lord.
3. Never forget to be grateful to one's partents.
4 Never forget to be grateful to one's teachers.
5. Never forget to be grateful to one's fellow human beings
6. Do nothing to offend gods, Buddhas, and one's elders.
7. Do not begrudge small children.
8. Do not burden others with your own troubles.
9. There is no place for anger and rage in the Way.
10. Do not rejoice at the misfortune of others.
11. Do your best to do what is best.
12. Do not turn your back on others and only think of yourself.
13. When you eat, be mindful of the hard work of the farmers who grew the food.
14. Do not dress in fine clothes, or waste time on superficial appearances.
15. Always behave with good manners.
16. Always treat everyone like an honored guest.
17. To overcome ignorance, learn from as many people as possible.
18. Do not practice and study the arts just to make a name for yourself.
19. Human beings have good and bad points. Do not dismiss or laugh at anyone.
20. Strive to behave well but keep good actions hidden and do not seek the praise of others.