Here is a great site with lots of links, geared towards helping kids understand divorce.
http://www.kidsturncentral.com/topics/issues/divorce.htm
here is another great site also.
http://www.divorceinfo.com/children.htm
Divorce is tough both on children and adults, but honesty is key in dealing with it along with not talking bad about the spouse.
Good luck and best wishes. Give the kids a big hug today.