Let's talk tangible first:
Kent's Mechanical Engineer's Handbook. Eleventh Edition. It is untainted with reaches beyond the scope of a saw and wet sand molds.
A new pocket reference for newer information.
My .357 single-action revolver, and re-loader, (honestly a skillet and a flintlock may supplant all the above, but not the following.)
A poster of Maslow's hierarchy of needs.
Plus knowledge. Knowledge that I must now Counter What Will Kill Me the Quickest. This is the title of a survival concept I wrote about based on Maslow's theory. Reviews of survival manuals reveal the sequential emphasize of shelter, fire, water, and not moving until help arrives. Yet, early chapters (2nd or 3rd) delve into edible plants and hunting/trapping techniques. It is too early in the reading. A manual should follow logical steps. So countering what can kill you the quickest seems logical. Dr. Dartnell directs us to build toward a level of comfort. A logical review of one's preparedness in this "knowledge experiment" lends to this Discussion topic and the path of the Dr.'s book.