The Jedi have had several mantra's through out the Star Wars time line. The oldest one was:
Emotion, yet peace.
Ignorance, yet knowledge.
Passion, yet serenity.
Chaos, yet harmony.
Death, yet the Force.
Jedi Odan-Urr changed it to the following:
There is no emotion, there is peace.
There is no ignorance, there is knowledge.
There is no passion, there is serenity.
There is no chaos, there is harmony.
There is no death, there is the Force.
After Return of the Jedi, Grand Master Luke Skywalker used the following:
Jedi are the guardians of peace in the galaxy.
Jedi use their powers to defend and to protect.
Jedi respect all life, in any form.
Jedi serve others rather than ruling over them, for the good of the galaxy.
Jedi seek to improve themselves through knowledge and training.
The last one, being the least esoteric, seems best for the Jedi Scout Padawans to memorize. For the older Jedi Scouts, the older mantras may be appropriate.
Any other teachings you recommend I add to this list, please let me know.