If you are referring to immigrant Latter-day Saints from the mid- to late-19th century, they were guided by both inspiration from God, and instruction from captains of companies of Saints.
Gilbert Imlay wrote The Emigrants.
R. K. Narayan wrote The Guide.
Many emigrants wrote "GTT" or "Gone to Texas" on their homes before embarking on their journey west. This served as a notice to neighbors that they had left for Texas in search of new opportunities.
The scientist that wrote this book was Chicago Tribune.
Jeff Danna
R.K Narayan
rk narayan
John Mason Peck has written: 'A gazetteer of Illinois, in three parts' -- subject(s): Gazetteers 'Daniel Boone' 'Father Clark' -- subject(s): Methodist Episcopal Church, Clergy 'A new guide for emigrants to the West' -- subject(s): Guidebooks, Description and travel 'A new guide to the West' 'The death of eminent men a public calamity' -- subject(s): Sermons
Lansford \Hastings
Two people actually wrote the guide to Teen Health : Ann McPherson and Aiden Macfarlane. (see the related link)
Rabbi Moshe ben Maimon.
Douglas Adams