1) every bank account she owned with identifying data;
2)every insurance policy she owned;
3)location of her will, house title, car title and boat title;
4)every health insurance card she owned (photocopies work fine);
5) list or location of any other assets, such as stocks, bonds, etc.;
6) location of checkbook;
7)location of recent bill stubs (invaluable to change address to have bills sent to administrator's house, or to cancel unnecessary services);
8)list of names and phone numbers of whom to call;
9) list of specific bequests (helpful even if informal); and
10)names and locations of preferred physicians and hospitals.
While she was healthy she signed a Power-of Attorney, a Living Will and Durable Power of Attorney for Health Care. The Power-of-Attorney was especially helpful to allow me to pay her bills while she was too ill to deal with such things, and made my transition to executrix easier after her death. I already knew what I needed to know by then. We also pre-arrainged her funeral while she was alive, together. I'm so glad we did.