Deeds and talents are often sprung from the imagination of an author, but the main point of the story is how the characters achieve the audience's approval.
Step one: Relate
Connections between the reader and the character could be the first step to your goal. For example, if the author decides to make his/her main character an orphan that was often bullied, people would naturally pity him or feel connected to him.
Step two: Flaws
Not all characters are perfectionists. If you start out with a character having amazing powers and great at everything, many people would be thinking 'If he is so good at everything, why do we need to commiserate him?' Plots are set to have the character learn something from their adventures and ordeals. Flaws are also a good way to tone down the arrogance level.
And @Rico W, you were right about there was more than just the label 'Good'. Not everything should have the good guys have a bad past and the bad guys having a good past. The 'Bad' characters might have a reason to become evil and the 'Good' characters might turn evil later on.
And lastly, you need to determine who do you want the reader to like and to trust. Also don't pick favorites among your 'Good' guys. Jealousy might arouse in the story.