Don't wait until you have extra in order to give something to someone, just share whatever you have eventhough it might be little. It is the act of kindness that the counts most and not so much the amount you give.
If you wish to do good or to give a helping hands to others, just do it. Do not ask any question or permission. If you do, normally people will refuse or reluctant to accept your offer or help. Give without asking because you understand their needs.