Ethics can essentially be divided into three general areas ([1]Internet Encyclopedia of Philosophy):

• Metaethics
  • Where our ethical principles come from.  Are they just an invention of society or is there a greater power at work?  Is there an intelligence to the universe that holds universal truths and values?
  • The second area of metaethics involves questions such as "Why be moral?"  This leads us to a number of theories:
    • psychological Egosism
      • believes that most of our actions are prompted by selfish desires.
  • psychological Hedonism
    • believes that pleasure is the motivator for all of our actions
  • psychological Altruism
    • we are hard-wired to instinctive benevolence
  • Emotion vs Reason
    • Are our decisions based on emotion, giving way to logic after the fact or based on logic with emotion layered on top.
  • Male and Female Morality
    • Are the differences between men and women reflected in the morality of each?
• Normative Ethics
  • • Is more practical.  What constitutes right and wrong?
    • The big assumption in normative ethics is that there is only one set of principles that constitute a universal moral code of conduct
    • The field of Normative Ethics can be subdivided into three theories:
      • Virtue Theories
        • Virtue ethics is based less on rules such as don't kill and more on basic 'habits of character'.  The theory being that, if I have developed the correct moral character, I instinctively will not kill.  
        • Aristotle argued that good moral habits involve finding the correct spot along a continuum.  For instance, too little courage makes on too timid but too much courage makes on too rash.
  • Duty Theories
    • The belief that we have clear obligations .  This is more along a set of rules that we need to follow without exception.  These duties can be further subdivided into duties to God, duties to oneself and duties to others.
  • Consequentialist Theories
    • We should determine our moral responsibility by wiethigh the consequences of our actions
    • "An action is morally right if the consequences are more favourable than unfavourable."
    • Can be broken down into three categories:
      • Ethical Egoism - An action is morally correct if the consequences favour me.
      • Ethical Altruism - An action is morally correct if the consequences favour everyone except me
      • Utilitarianism - An action is morally correct if the consequences favour everyone.

• Applied Ethics

• Essentially, applying our ethical principles to particular issues such as euthanasia, war, abortion and so forth

References:

[1]  The Internet Encyclopedia of Philosophy:  http://www.iep.utm.edu/ethics/#SSH1b.i