Whenever I write about things people need to know in estate planning, it generates a lot of email from readers.

That was especially true with the article about common mistakes people make. What seemed to resonate with readers was the caution about beneficiaries.Financial experts tell us one of the most common mistakes they see in estates is failing to list beneficiaries or to keep them current.They emphasize you need to list everyone you want to get your money when you pass away.In other words, if you want all your children to share in your estate, ALL have to be listed as beneficiaries.An email from an Emmaus woman said she believed the will she made was foolproof. Her will said all three of her children should share in her assets. But only her son was listed as beneficiary of her bank accounts.After reading my column on estate planning she asked her lawyer if I was right in saying if only her son's name was listed as beneficiary, he could do what he wanted with the money, despite what the will said.The lawyer told her she needed to list all her children as beneficiaries, if she wanted all of them to share in the money.Another man told a similar story, but this time he said it was his sister who deliberately misled their mother. He wrote back to say his mother made the changes to ensure both children were named as beneficiaries.I recently attended a seminar at our local college that was billed as "Estate planning issues for second marriages."I'm not a person who believes in running to lawyers. Yet, the most important thing I got out of that seminar was that for those planning a second marriage, the most important person they need to see is not a wedding planner. It's a lawyer.When we're young and getting married for the first time, most couples starting out have few assets. Over the years they work together to build a nest egg they can leave to the next generation.But what happens when one spouse dies and the remaining one remarries?According to the seminar lawyers, issues like that should be mutually decided before marriage."If you want your children from a first marriage to share in what you have, you need to have a trust or estate plan that guarantees your wishes will be followed," stressed the lawyer.If this isn't done, in many cases the children from a first marriage are denied a share of their parent's money. In other cases, it's the second wife who gets cheated.The lawyers presented some real-life scenarios where failure to do a prenuptial or estate trust meant serious legal problems for the family.Yet, think about this: When you're in love and planning to be married, who sits down to address who will get what assets when one spouse passes away?Even those who think they have taken steps to protect both a new spouse and children from a first marriage may make big mistakes if they don't have a good lawyer familiar with family law.In one such case, a man marrying for the second time wanted his daughter from his first marriage to inherit his house when he passed away. But he thought he made provisions to protect his second wife by stipulating in his will that she be given a lifetime estate in the home.In other words, his second wife could live in the home until she passed away - then the home reverted to his daughter.That's a common solution many use.When the husband in this case was killed in a motorcycle crash, his wife knew she would at least have a roof over her head.But it was the roof in question that did her in.A big storm did a lot of damage to the house because the house needed a new roof.Since the wife didn't own the home, (the daughter did), she believed the daughter should pay for the repairs along with the new roof.The daughter refused, saying the person living in the house is responsible for maintenance.Who was right?The law clearly says the person living in the house is responsible for bills. Because the second wife had no money to pay for the new roof, she had to move from the house.What she didn't know was that she was entitled to a one-time family allowance of up to $18,000. Because they lived in Florida, a state that has laws to protect a surviving spouse, the wife was also entitled to an elective share of the homesteaded house if she never signed that right away.There are a lot of legal issues here that needed to be addressed while both spouses were living.I'm not a lawyer and this column doesn't pretend to offer legal advice.But I will say this: If you're planning a second marriage or already in one, you need a lawyer to define your rights and make sure all parties are protected.At the very least, at the start of a second marriage partners should have open discussions about financial issues then follow up with legal advice so there are no nasty surprises.