There are two (?) main types of moral systems: rules-based and virtue-based.

Rules-based systems can be as simple as, "Do unto others as you would have done unto you" or the Ten Commandments, or as complicated as the ancient Hebrew laws as laid out in Leviticus and other books of the Pentateuch in the Bible.

Virtue-based systems hold that actions are a result of character, and character is determined by virtues, so we should cultivate virtues that lead to right actions, and choose actions in accordance with our virtues in a "virtuous" reinforcing cycle.

Neither system alone gives entirely satisfactory answers in every situation, and most people in real life use both.

The number "seven" is an ancient sacred number, so in Western European culture, you will often hear about "The Seven Virtues" although other numbers are given, of course. And other cultures have their own systems.

Western Europe

From http://webcentre.co.nz/kk/peerage.htm :

The Cardinal Virtues:

temperance (sometimes restraint), prudence, fortitude (sometimes courage), justice -- as approved by the Greek philosophers such as Plato, and later the Church

The Theological Virtues:

love/charity, hope, faith -- St Paul's preference, not inherent but conferred at baptism

The Seven Contrary Virtues:

humility, kindness, temperance, chastity, patience, charity, diligence -- so-called because they are traditionally set against the Seven Deadly Sins, originating from Psychomachia by fifth-century poet Prudentius

The Seven Heavenly Virtues:

faith, hope, charity, fortitude, justice, temperance, prudence -- combining the Cardinal and variants on the Theological

The Knightly Virtues:

prudence, temperance, justice, fortitude, humilty, compassion, courtesy, devotion, mercy, purity, peace, endurance -- said to be represented in the arms and points of the cross of the Order of St John

The Courtier's Virtues: