While slightly outdated, this is a very good article that summarizes the need for estate planning and how to approach it. The key point here is that everyone should have an estate plan as a necessary part of any financial plan or strategy. Too many people do not have wills or have outdated documents (the latter can sometimes be more dangerous than the former).
Estate planning does not have to be scary or expensive. The topic is uncomfortable and there is nothing you can do about that but you can do it yourself if you are so inclined (and have a relatively uncomplicated plan) or you can hire a professional to help you. It does not, and should not, cost a fortune.
I would encourage everyone, no matter how much money you have or think you will have, to review your estate plan.