In my opinion, the most important part of financial planning for the family is planning for the retirement of the married couple or parents. I think that all other aspects sort of flow out of this.
The parents' first responsibility, I think, is to take care of themselves. This is, of course, within reason. They should not be selfish, but they do need enough to be secure in their retirement so they will not be putting demands on their children.
With this in mind, the family should create a budget that will allow them to save for retirement and (hopefully) for their kids' college as well. The family must understand how much they need to put away each year or each paycheck and then decide what things they can afford based on that goal.
I think the most important part of financial planning for the family is keeping your expenses, income, and budget in order. Most of financial planning varies from family to family and person to person, but for the most part that is the best suggested plan of action. As previously stated, it varies from person to person, and some of those variables include debt, income, living situation, where in the world you live, how many people are in your family, and quite a few others. but keeping track of all of your expenses and setting a budget are a great way to help keep family finances in order.
Hope this helps!
Keeping a book which contains all your expenses and incomes