This article about the old and new Baedekers travel guides has some great quotes, ranging from the ludicrous:
Readers were often advised to take full evening dress, a pith helmet and a medicine chest as well as a large number of suits and dresses.
To the insulting:
Travellers a century ago were also advised how to keep out of trouble. Don't be rude in Spain, they were advised in 1913, because it serves only to "excite the inflammable passions of the uneducated Spaniard".
Similarly stern were the judgements on whole populations. The Italians cared little about dirt, Americans spat too much, while ordinary people were judged on a scale from docile (Egyptians) to uppity (the Spanish).
To the very old fashioned:
In a Baedeker phrase book from the 1890s, potential servants were greeted with the words: "You must be exact in the execution of my orders, and if you happen to get drunk, I shall dismiss you at once."
The most interesting part though, is:
The world wars were disastrous for a German company reliant on the free flow of wealthy Europeans, but the books did prove useful to soldiers and airmen. The Baedeker raids of 1942, the bombings of historic English cities, were so-called because the Luftwaffe had supposedly vowed to destroy every British building marked with three stars in the guide.
You can read more about the Baedeker raids on Wikipedia and here and here on the BBC. I just find it rather humorous you could be bombed for making it into a guidebook, a feat most establishments strive for. Ironically, all the dives were safe, which is a shame, because I've stayed in a few places which could have been improved by a bombing raid.