The son of a book printer, Baedeker was born in Essen, then in the Kingdom of Prussia, and started his publishing company in 1827 in Koblenz. Baedeker's company in 1832 bought another Koblenz publisher (Friedrich Röhling) which had in 1828 published a handbook for travellers by J. A. Klein, under the title Rheinreise von Mainz bis Köln (travelling the Rhine from Mainz to Cologne). This provided the basis for the first of the Baedeker travel guides.

The red bindings and gilt lettering soon became the familiar hallmark of Baedeker's guides, and the content became famous for its detail and accuracy. While the travel guide was not a new form (Baedecker followed the model of English guide books instituted by John Murray), Baedeker's innovation was to include specific details of transportation, accommodations, prices, and so forth. Starting in 1844, he augmented this with star ratings for attractions. Baedeker was famous for his careful work; when visiting Milan Cathedral in 1847, he was observed to drop a pea at every twenty steps of the staircase to the roof, so as to be able to report the number of steps accurately. Eventually his guide books were issued in English and French as well as in German.

His cousin Friedrich Wilhelm Baedeker (1823-1906), who joined the Plymouth Brethren movement, was also well travelled. Early in his career he sailed to Australia following professional pursuits and after 1866 in Christian service travelled to Sweden, Russia and Siberia, preaching to prisoners and aristocracy.