I call divorce the big "D". The big "D" represents more than the word divorce. Devastation, Destruction and Dysfunction are all part of the big "D". Not only do we, the adults, have to deal with divorce, our children have to deal with the aftermath of the decision too.
You may feel that you've explained everything to your kids, but be prepared to repeat yourself calmly and patiently if your child simply refuses to understand. Your child may not be able to take in the information for some time or may only be able to take it small, digestible pieces.
If you child questions where daddy or mommy has gone, be as clear and as factual as you can. Don't lie, but don't hit them with brutal truths either (daddy ran away with another woman). Explain that you are in contact with their other parent and describe where the other parent is living if possible.
Your child may be fearful that their other parent isn't coming back. Wait till you are comfortable with your relationship with the other parent before addressing this. If that's not possible, before speaking to your child on this subject, bear in mind that it is confusing to a child to be told one thing and then to have that contradicted. Not knowing is better than pretending to know, not only for your child, but for you as well.
If your child asks you if it's their fault that their other parent went away, you must make certain that they understand that absolutely was there no way it was their fault. Try to explain that divorce is something between adults or "big people". Depending on the age of your child, you might be able to communicate the reasons (again, avoid brutal truths), that you and their other parent are unable to stay living together as a family. But remember that adult reasons don't always cut the ice with kids. You could end up with a lot of "buts" and "what ifs". As a rule, children are more interested in the effects of the split-up on them than they are on the effects of marriage to you.
One common question that children of all ages have is if their other parent still loves them. This question may be spoken out loud by younger children, but often goes unasked by and struggled with by older children. It is important that you reassure your child that whatever has happened between you and their other parent has nothing to do with the way either of you feel about them. It is also comforting for your child if they know that the parent that they do not live with, will be okay and will be able to manage on their own. This common anxiety can be calmed with your reassurance. It is hard to strike a balance between acknowledging all that will be missed and grown-ups ability to cope.
You might find yourself in a situation where something happens and you are unable to hold back tears in front of your child. Your child will recognize that you too are sad about what has happened. Don't try to camouflage your tears with excuses of something in your eye. Tell your child the truth, that you are sad and sometimes you cry, just like them, when you get sad. Your honesty (don't over-do-it) will encourage theirs.
A natural anxiety among older children, is whether divorce is catching. Especially among older children. Reassurance and understanding are important; managing your guilt in the face of the implicit criticism will be the painful bit for you. Remember too, that children may suffer a fear of total abandonment by their non residing parent. Or worse yet, an anxiety that the other parent may not be their parent anymore. Explain that people can stop being someone's husband or wife, but they can never stop being someone's mother or father.