I'm an attorney and one of the main focuses of my practice is Estate Planning. Please, for the love of everything good in the world, don't try to do these documents yourself. You would not believe how many people come in and either they, or their family, have to pay way more to us to fix the mess caused by incorrectly produced documents than they would have paid to us to do the documents properly the first time.
Almost all of the documents have state specific requirements that companies like Legal Zoom and Rocket Docs don't conform to. And their customer service reps can't give you the necessary legal advice to do the documents so they properly conform to your state's laws.
As much as the internet would like you to believe, this is not a simple area of law. Professionals exist for a reason. We're here to help you and make sure you're taken care of in case something happens.