Here are a list of men's organisations that can help you - however you should also read our section on Children carefully as there is a lot of useful and practical advice.
On a personal note from the Itsfinished.com site author...
"Most parents strive to keep their divorce settlements from court and will put their children's interests before their own. A lot of women recognise that the court system discriminates against men and are angry that this is the case - positive discrimination does little for women's rights or to further anyone's cause.
However if you are reading this and are in the unfortunate position of a very close friend of mine then you will have an ex wife whose hatred is so intense that she will use and hurt her own children to get back at you and will screw you for every penny even though you may have been the sole income provider for the family! Believe it or not the court system will actually help her to make you bankrupt and unable to see your own children - in fact she may even be rewarded for emotionally abusing them with further financial assistance from the CSA!
It's tough, I make no bones about that, but if you do lose contact, it does get easier. Years later and my friend still has no contact with his now grown up children - but he is happy having found new meaning in his career, friendships and a new relationship.
I hope it doesn't come to that for you - do everything you can to keep it out of court and settle things amicably, and if your ex is anything like my friend's, seek support. There are plenty of organisations listed to the right that can help you."