M.D.
Unfortunately I DO have experience with this since I was widowed before dd was born and my husband had 2 older sons from his previous marriage.
A trust is a great idea so that you can have control over what is done with your money even after you are dead. You can put stipulations in a trust that your kids get x amount at x age, and addtional amounts at additional ages.
For example, my trust stipulates the percentages that go to each child and at what ages. At age 25 they are allowed to have 25% of their money, at age 35 they get 50% of what is left, and at 45 they get the remainder. Also, I do allow them to get it early for education purposes only, or extreme medical circumstances. And I chose a trustee that I trust to govern this money and make wise decisions with it.
This way your kids can't squander your hard-earned money on frivolous things.
I paid about $300 to have all the legal paperwork drawn up (this included a few meetings with the lawyer to talk about options and refine and clarify things).
I think a trust makes everything neater, easier, etc.
Good luck. I have the name of a good attorney if you want for this.