Our gaming group actually put together a code for Paladin's, maybe it can be useful to you. Now as for any LG characters, talk to your DM, but like I said maybe this will help for Paladins.
"The Paladins code is by no means an oath that one accepts lightly. To be a Paladin is to exhibit the best qualities in men, and display none of their weaknesses. Many men try, but cannot live up to the ideals of the code and as such falter. All Paladins adhere to said code without regret or remorse. There are many knights in the world, many noble men. But very few of these are Paladins. Paladins are shining beacons of hope, in an otherwise dark world. They are both feared and respected by their enemies, precisely because they alone adhere to this unwavering code. This code shall be adhered to at all times even if doing so leads to your death.
• Faith: Serve always the true lord your god. Keep faith in your beliefs, for faith roots you and gives you hope against the despair that human failings, and the darkness of the world create. Paladins apply their faith to all aspects of their life. In addition to assisting their church, they freely lend aid to others, and take it as an opportunity to spread the good will that their faith has given them. Men often lose hope, and Paladins aspire to instill hope and goodwill to all.
• Hope: Bring light and hope to all parts of the world. Seek out evil in all of its forms, stand before it, and vanquish it without pause or remorse. Paladins are the sword of the gods. Without question they are both hated and feared by all who fear the powers of good. In most cases Paladins are the primary targets when involved in a confrontation with evil, even more so then clerics. This is because the Paladins unending thirst to destroy evil, is widely known.
• Defense: Seek always to defend the weak, your liege, your nation, your family, and those to whom you believe worthy of your loyalty. Paladins will always protect those they see as innocent or weak, friends, family, or those they serve. If a Paladin were to come upon a burning building and hear screams inside, he would without pause or thought of his own well being, charge into the building and attempt to help its occupants.
• Loyalty: Be known for unwavering commitment to the people and ideals you choose to live by. There are many places where compromise is expected; loyalty is not amongst them. Paladins are always loyal to those they associate with. If a friend was captured and taken to a castle to be tortured for information, the friend need not worry, for it is understood that the Paladin will do all in his power to find and rescue him.
• Prowess: Seek excellence in all endeavors expected of a knight, martial and otherwise, seeking strength to be used in the service of justice, rather than in personal accomplishment. Paladins seek to be excellent in all that they do. If a Paladin uses a sword, he attempts to master the sword. Every day he will train or engage in warfare, and it is likely will never stop in that endeavor, until of course he cannot find an equal in that skill. This is true with any pursuit be it weapon play, or dancing. For this reason, Paladins choose their activities wisely.
• Justice: Seek always the path of 'right', unencumbered by bias or personal interest. Recognize that the sword of justice can be a terrible thing, so it must be tempered by humanity and mercy. If the 'right' you see agrees with others, and you seek it out without bending to the temptation for expediency, then you will earn renown beyond measure. Paladins uphold the law, and seek to ensure others do the same. A Paladin will only intentionally break a law, if he deems the law to be unjust, and even then he would rather seek to change the law then to break it outright.
• Courage: Always speak the truth, and have the strength to take the side of truth in all matters, rather than seeking the expedient lie. Seek the truth whenever possible, but remember to temper justice with mercy, or the pure truth can bring grief. Paladins do not lie. Paladins seek truth in all aspects of their life. They will not abide liers, and will often not wish to associate themselves with those that do.
• Courtesy: At all times be courteous to women, for they hold the power to breathe life into the world, and should be respected for such a gift. Paladins will always be respectful of women. Even if said woman is an enemy.
• Humility: Be humble before others, especially superiors. Be not boastful. Value first the contributions of others; do not boast of your own accomplishments, let others do this for you. Tell the deeds of others before your own, according them the renown rightfully earned through virtuous deeds. Paladins do not undertake dangerous assignments for the glory. They leave the glory to be had by others.
• Largesse: Be generous in so far as your resources allow; largesse used in this way counters gluttony. It also makes the path of mercy easier to discern when a difficult decision of justice is required. Paladins are very generous with their worldly possessions. Money, clothing, food, all are given to those in need. Many Paladins are remembered for their seemingly unending generosity.
• Nobility: Seek great stature of character by holding to the virtues and duties of a knight, realizing that though the ideals cannot be reached, the quality of striving towards them ennobles the spirit, growing the character from dust towards the heavens. Nobility also has the tendency to influence others, offering a compelling example of what can be done in the service of rightness. Paladins view nobility not as a birthright, but as something that each man must earn. Aspiring to greatness lifts the spirit. Paladins act in a matter befitting the best of nobility at all times.
• Mercy: Show mercy to defeated enemies. Mercy is not for the weak. It takes the strongest of men to refrain from killing a foe, and such strength does not go unnoticed. When an enemy falls and cowers before a Paladin, the Paladin will grant him mercy, and not take his life. Instead he will take all power from the enemy, ensuring he can do no more harm. In many cases this implies returning the foe to civilization to serve trial. The outcome of which is not the Paladins concern.
• Franchise: Seek to emulate this code as sincerely as possible, not for the reason of personal gain but because it is right. Do not restrict your exploration to a small world, but seek to infuse every aspect of your life with these qualities. Should you succeed in even a tiny measure then you will be well remembered for your quality and virtue. Not only will the Paladin live by the words of this code (or the letters of the law), he will also strive unendingly to live by its ideals (the spirit of the law). Paladins hope to die in service of the powers of good, so that their death is remembered, and inspires others to rise up and take their place against the forces of darkness."