O people, the LORD has told you what is good,
and this is what he requires of you:
to do what is right, to love mercy,
and to walk humbly with your God.
Micah 6:8
One of them, an expert in religious law, tried to trap him with this question: “Teacher, which is the most important commandment in the law of Moses?”
Jesus replied, “‘You must love the LORD your God with all your heart, all your soul, and all your mind.'This is the first and greatest commandment. A second is equally important: ‘Love your neighbor as yourself.’The entire law and all the demands of the prophets are based on these two commandments.
Matt 22: 35-40
While I hesitate with the use of the word love as it has become so twisted in today's society, these are still the verses I'd point you towards for a way to determine whether a certain action is good or not and a few quick principles to put in your pocket. Also 2 Peter 1 is excellent.