wa'alaikum as'salaam,
I did some more research on this and I was a bit wrong in some of the things I said, it's been a while since I used this information. Here's what I found about maintenance for ex wife and children....
The revocably divorced woman (i.e., first or second talaaq) is entitled to maintenance during her ‘iddah, and it is not permissible to make her leave the house, because of the words of Allaah (interpretation of the meaning):
“And turn them not out of their (husband’s) homes nor shall they (themselves) leave, except in case they are guilty of some open illegal sexual intercourse. And those are the set limits of Allaah. And whosoever transgresses the set limits of Allaah, then indeed he has wronged himself. You (the one who divorces his wife) know not it may be that Allaah will afterward bring some new thing to pass (i.e. to return her back to you if that was the first or second divorce)” [al-Talaaq 65:1].
Allaah says (interpretation of the meaning):
“And for divorced women, maintenance (should be provided) on reasonable (scale). This is a duty on Al‑Muttaqoon (the pious)” [al-Baqarah 2:241]
This maintenance is obligatory in the case of a woman who is divorced before consummation, if she did not have a specified mahr at the time of the marriage contract, because Allaah says (interpretation of the meaning):
“There is no sin on you, if you divorce women while yet you have not touched (had sexual relation with) them, nor appointed unto them their Mahr (bridal-money given by the husband to his wife at the time of marriage). But bestow on them (a suitable gift), the rich according to his means, and the poor according to his means, a gift of reasonable amount is a duty on the doers of good” [al-Baqarah 2:236].
But if the divorce came after consummation, then maintenance is not obligatory according to the majority of fuqaha’, rather it is mustahabb.
http://islamqa.com/en/ref/126281
Maintenance of children is a duty of the father, according to scholarly consensus, whether he remains married to his wife or divorces her, and whether the wife is poor or rich. She is not obliged to spend on the children when their father is still alive.
The woman who has been given a revocable divorce (first or second talaaq) must be given maintenance and accommodation during the ‘iddah, but when her ‘iddah ends, if she is not pregnant, she is not entitled to that.
In the event that custody of the children is given to a divorced woman, then the children’s maintenance must be paid by their father, and a mother who is breast-feeding may request payment for breastfeeding the child.
Maintenance of children includes providing accommodation, food, drink, clothing and education, and everything that they need, on a reasonable basis, depending on the husband’s circumstances, because Allaah says (interpretation of the meaning):
“Let the rich man spend according to his means; and the man whose resources are restricted, let him spend according to what Allaah has given him. Allaah puts no burden on any person beyond what He has given him. Allaah will grant after hardship, ease” [al-Talaaq 65:7]
http://islamqa.com/en/ref/89708