I would definitely add maps. If you want to keep a zero budget you can always print them off the computer and laminate them. I carry three types, state, multi-state (all adjoining states) and a map of my work building. The map I have for work is just a mini blueprint, but it shows all fire exits and has the dimensions clearly labeled. This makes it easy to navigate if the power goes out.
_________________________
Spemque metumque inter dubiis - Hover between hope and fear. (Vergil)