Children generally do better if given accurate information and the specifics that they ask for. Children should be encouraged to attend funerals and be involved in grieving. Tthe best way to do this is to ask them if they want to go and make arrangements for a somewhat uninvolved adult to be with children so that if they need to leave a funeral service, the adult with them is not centrally involved in the service and can leave with the child. Use words the child understands. Avoid jargon or long explanations.
Short sentences are also better.
Give them time to digest what you have said. Answer questions honestly but in the scope of what the child understands. Have faith that the child can hear emotionally difficult issues. This one is difficult especially when you are bereaved as well. Let the child act physically.