The best definition available. For a simpler lesson, the Khan Academy has some useful beginners’ lessons.
An accessible and complete how to guide to surveying created by the state of Oregon.
A very readable short history. A more detailed British perspective and a more critical Indian one are also available. For the major contributors to the survey, a British history of George Everest and a biography of Radhanath Sikdar , the first person to correctly calculate the height of Everest.
Shown below are the locations of K2 and Mount Everest in the Himalayas. To see the Himalayas turn on the “terrain”layer on the upper right hand side of the map.
View Himalayas in a larger map
Recommended books:
John Keay, The Great Arc: The Dramatic Tale of How India was Mapped and Everest was Named
Mathew Edney’s classic Mapping an Empire: The Geographical Construction of India,1765-1843