A guidebook was a publication designed to help visitors navigate their way around unfamiliar territory.
When given A Cadet's Guide to Sector 001 Earth by Miles O'Brien and Julian Bashir as a gift prior to his attending Starfleet Academy in 2372, Nog was corrected in his assumption that it was a guidebook by O'Brien, who clarified that it was "a completely interactive program detailing Earth's customs, culture, history, geography".
Nevertheless, after time traveling back to 1947 Roswell, he referred to it as a guidebook when explaining to Rom and Quark that the Humans who were attempting to communicate with them were from the 20th century, as he recognized their military uniforms from the guidebook. He erroneously believed they were Australian, though. (DS9: "Little Green Men")