Get an attorney unless you don't have anything, then it doesn't matter. Don't leave your family with an expensive mess to clean up. I'm in the Real Estate industry you can't believe the messes I have seen. Find an attorney that specializes in estates get it done right. You wouldn't operate on a family member by reading the internet.
Your different IRAs and 401s each have different characteristic and if your family does not know how to handle they will face penalties.
Then get a financial planner who can give you advice to pass on the most money. DO NOT find a financial advisor. There is a difference. Need help, pm me and I will tell you where to find qualified people.
If you have a very simple estate, uslegalforms.com has documents that will help. Very important to make sure you're using a state specific form as estate laws vary state to state and the laws of the state you reside in will apply to your estate. If your estate is significant, then it would be wise to hire a good estate planning attorney. It's very wise to sit down with everyone affected by your will afterwards to explain what the will says. That way you can settle any disagreements while you are alive and take that pressure off of your executor. Lay out the plan to everyone so there is no surprises and no one is confused about what is going to take place. It's also an act of love to your family to have all of your important documents all in one place and include an instruction sheet with instructions on what you want done and also describing all of your accounts and assets to make it as easy as possible for your family to carry out your final wishes.
HSLDS who defends it if there are mistakes made. You can have attorney review it. Problems arise his answer will be I didn't write it I won't defend it. If you have a decent estate and love your family don't put them in a place where they don't know what to do. If it is wrong you won't be around to help.
Believe me I don't like to spend money on attorneys, but sometimes it pays.
I have a simple estate - my son will get all. I did my will via an on-line program and had one of my best friends review it - he is a lawyer and the executer of my estate.
He was stunned at how good a job the program did.
I agree that review by a lawyer is not bad, but his comment was the more specific you can be, the better - write it down, explain it in the will and all the wiggle room goes away (he also suggested putting in what you do NOT want to happen...).
Anybody see the real problem here? You cannot as a citizen pass on your estate, simply, without risk of it being taken away from whoever you meant to have it. You need a lawyer to write instruments to protect your estate from lawyers who want to take it and those instruments are not a guarantee that will not happen. Greed is a diasese that effects all.