I'd like to recommend that Logos add Who Needs Theology? An Invitation to the Study of God by Stanley J. Grenz and Roger E. Olson (IVP Academic, 1996). It's a great starter book for people who are not sure what theology is, or who have only the vaguest notion about why it's important, or maybe even those who are afraid of theology (thinking it adds something "extra" -- doctrines of men -- to what's in the Bible) but are at least willing to explore someone's gentle explanations that maybe they're misunderstanding and are afraid of the wrong thing.
For most Logos users it might be unnecessary, but maybe it would be a helpful resource for how to communicate with friends.