How to become a good human being?

Here are five things that come to mind:

1. When possible, don't preach.  Let your actions speak.
2. Resist becoming Mr./Mrs. "fix it all."  When people share something with you, listen, don't offer advice unless it's asked for.  Most of the time, people will ask for your advice if they really want it.
3. With all due respect to the charitable organizations asking for donations through TV ads, consider helping those closest to you, those around you, first.  Consider this thought experiment: if you chose to help "others" instead of those closest to you and everyone else did the contrary, who would help your loved ones?
4. Inspire others.  I've found that one of the most effective ways to do this is to lead by example.
5. Become more compassionate.  We all deserve a chance to become better.  When you hear about so-and-so in the news doing this, that, or the other, try not to be so quick to judge, and instead realize that so-and-so may very well put you to shame one day should this person get their act together, and you continue hating, judging, and condemning others for their mistakes and shortcomings.