In the book itself, the guide was from the publishing houses of Ursa Minor. The books you can buy were published by Random House.
pan books
Pan Books published the Hitchhiker's Guide. The Wikipedia page is here: http://en.wikipedia.org/wiki/Pan_Books
The production budget for "The Hitchhiker's Guide to the Galaxy" was approximately $50 million.
Douglas Adams's Guide to The Hitchhiker's Guide to the Galaxy was created in 1979. It was published as supplementary material to his radio series.
The Hitchhiker's Guide to the Galaxy was released on 04/29/2005.
The ISBN of Douglas Adams's Guide to The Hitchhiker's Guide to the Galaxy is 0-563-55236-0.
The Hitch-Hiker's Guide to the Galaxy is 100% fact in the 42nd dimension.
The Hitchhiker's Guide to the Galaxy as international phenomenon was created in 1980.
The Hitchhiker's Guide to the Galaxy grossed $104,019,112 worldwide.
Baedeker
The publisher of the book "Your Child: A Medical Guide" is the Editors of Consumer Guide
The ISBN of The Hitchhiker's Guide to the Galaxy - novel - is 0-330-25864-8.