Listed below are the lengthy guidelines for paladins in my campaign.
If you have suggestions that you think would fit and help clarify, or not-too-uncommon circumstances I didn't think of, feel free to post them, so that I can consider adding them.
Paladin Code of Conduct These should give you an idea of what is expected of you. Some things will vary based on your chosen deity. For example, under prisoners, if you are serving a God of mercy, you might be required to give quarter no matter how many times that individual has escaped or evaded the law in the past. For a warlike god, it might be more acceptable to dispense justice on the battlefield. The guidlines below represent a fairly militant and hard-lined church.
o Do not lie This includes any form of INTENTIONAL deception, including intentional ommision of information with the intent to mislead. There are no WHITE lies. You do not lie about who you are or what you doing. You may not answer, but to lie is unforgivable.
Your word is your bond.
o Do not steal In an emergency to save the world, stealing a horse is NOT ok.
Taking it and leaving the usual charge would be ok, but you must return to insure that the price you 'paid' was the asking price.
If any hardships were incurred by you 'buying' the horse, you would be responsable for reperations.
o Be Honorable (especially in Combat) You must engage the enemy in an honorable fashion.
-Do not attack from behind This includes attacking from any fashion where the opponent does not know you are there, and cannot be prepared for the battle.
Creatures which can 'see' in all directions, can be attacked from any direction, but not from hiding (inv).