Who is the author of book called The Guide to Galaxy?

The book you're referring to is likely "The Hitchhiker's Guide to the Galaxy" written by Douglas Adams. It is a humorous science fiction novel that tells the story of the adventures of Arthur Dent and his friend Ford Prefect, who hitch a ride on a Vogon spaceship after the Earth is destroyed. The book is known for its satirical humor and its exploration of philosophical themes. Douglas Adams wrote five novels in the series and it has been adapted into several films, television series, and radio shows.