Hi J. - It sounds like you need the advice of an estate attorney. There are many options for you, a trust among them. Let me tell you this though - there will be no capital gains tax issue for you if you have lived in your house for a long time, which it sounds like you have. You can sell it for up to $250,000 with no taxes - that's pretty cool!
Otherwise, you can set up ownership of your house now on your deed with your son, or you can will portions to your children. You have lots of options!
In order to do any of this however, you will need to speak to an attorney - so why not do it now? Talk with your children, then to an attorney. You are smart to be thinking about this all now - though they might not like it.
It will feel better for you to have these affairs in order as you move forward. Good luck!