What do I need to know about my parent's estate in the event of their passing? Will, etc? Need your help!

So unfortunately my dad is not doing so well and there have been conversations today that I do not believe my mom and I were ready for.

With this in mind, what do I need to know about my parent's and the estate?

I am thinking along the lines of

*Do you have a will? Where is it located?

*Do you have life insurance? Who is it through?

*etc.

My friends, Is there a good website that lists these questions that as a responsible son I should know in the event of a passing of my parents? Apologies if this has already been asked in a previous post and greatly appreciate any advice!