Recording in a quiet place, edit and mix master tapes in digital, and use low noise, good quality voice tape for copies. Today consumers expect good sound. Use a script. A script assures you give listeners a solid, organized, effective presentation. Pare away fluff, and carefully reconsider anything distracting or unclear to your audience, before you record.
All writing involves rewriting.
A professional voice may be an easier, less expensive way to go, rather than using the author. If you'll be the voice on tape, rehearse, rehearse, rehearse. Record, edit and store your master tapes in digital format. Test covers and titles before doing a large duplication run. Pick a supplier who also replicates CDs, and who can assemble your tapes into packages and ship to more than one location.