These are some of the laws of Charity...
http://www.torah.org/learning/halacha/classes/class95.htmlChapter 34: 1-3The Laws Pertaining to Tzedakah1. It is a positive mitzvah to give charity to the poor of Israel, as [Deuteronomy 15:8] states: "You shall surely open your hand for him," and [Leviticus 25:36] states: "And your brother shall live with you." Whoever sees a poor man requesting help and turns away from him without giving him charity violates a negative command, as [Deuteronomy 15:7] states; "Do not close your heart or shut your hand from your poor brother."
Charity is the sign of the descendants of our Patriarch Abraham, as [Genesis 18:19] states: "for I know him; that he will command his children... to perform tzedakah."
The throne of Israel will not be established and the true faith will not stand except through tzedakah, as [Isaiah 54:14] states: "I shall be established through tzedakah." Giving tzedakah supersedes all the sacrifices, as [Proverbs 21:3] states: "The performance of tzedakah and judgement will be more desirable before G-d than an altar." Israel will be redeemed only through tzedakah, as [Isaiah 1:27] states: "Zion will be redeemed through judgement and those who return to her through tzedakah."
A person will never become poor because of giving tzedakah, nor will any evil or damage come because of tzedakah, as [Isaiah 32:17] states: "The work of tzedakah is peace." Whoever, shows mercy will have mercy shown towards him, as [Deuteronomy 13:18] states: "He will grant you mercy, have compassion on you, and make you flourish." In contrast, the lineage of anyone who is cruel is a matter of question.
The Holy One, blessed be He, is close to the call of the poor, as [Job 34:28] states: "And He hears the cries of the poor." Accordingly, one should take great care lest they cry out, for a covenant has ben established with them, as [Exodus 22:26] states: "And it shall come to pass that he will cry to Me, and I will hear, for I am compassionate." The Jerusalem Talmud (see Shir Hashirim Rabboh 6:11) states: "The door which will not open for the poor will open for the physician."
A person should meditate on the fact that, at every moment, he asks G-d for his livelihood. Just as he requests that the Holy One, blessed be He, hear his cry, so too should he hear the cry of the poor. He should also meditate on the fact that the wheel of fortune turns constantly, and ultimately either he, his children, or his grandchildren will need to receive charity.
A person should not think: How can I reduce my wealth by giving it to the poor? He must realize that the money is not his, but rather a trust granted to him in order to carry out the will of the One who entrusted it to him. This is the portion which he will ultimately receive for all his labor in this world, as [Isaiah 58:8] states: "Your tzedakah will proceed before you." Tzedakah wards off harsh decrees and prolongs one's life.
2. Every person is obligated to give charity according to his potential, even a poor man who derives his livelihood from charity. If he has some money of his own which he does not invest in business, he is permitted to take charity since the principal is not invested in a manner which will allow him to live off the profits. Nevertheless, since he has a base which could provide an income, he is obligated to give tzedakah from what is being given him.
Even if he is able to give only a small amount, he should not hold himself back, because the small amount he gives is equivalent to a large amount given by a rich man. In this vein, {Menochos 110a] states: When [Leviticus 1:9] describes a burnt offering of a beast, it uses the expression "a fire-offering, a pleasing fragrance"; when it (ibid. 1:17) describes the burnt offering of a fowl, it also states: "a fire-offering, a pleasing fragrance"; when it (ibid. 2:9) describes the meal offering, it also states: "a fire-offering, a pleasing fragrance." This teaches that there is no difference whether one gives a lot or a little, so long as one directs one's heart to one's Father in Heaven.
Nevertheless, anyone who has no more than what is necessary for his own livelihood is not required to give tzedakah, for one's own livelihood has precedence over that of any other person.
3.How much should be given to poor person? "Enough to meet all his needs" (Deuteronomy 15:8). This applies to a poor man who receives charity without anyone knowing of it. The people of his city are obligated to give him enough for all his needs, allowing him to maintain the same standard of living as before he became impoverished.
In contrast, if a poor man goes around collecting alms, it is necessary to give him a small donation according to his stature. At the very least, in the entire city, he should be given enough bread and food for two meals each day and a place to sleep.
We must support and clothe the gentile poor together with the Jewish poor, as an act of peace.