Story of Jackets

The Story of the Dustjacket
The Victoria and Albert Museum in London has an interesting article about the history of the dustjacket.

There is also a Wikipedia article on the subject.

The image shown here is of the 1908 1st issue dustjacket for Kenneth Grahame's The Wind in the Willows, typical of the era. Printed on simple but strong brown paper, the jacket copies in ink what is applied as gilt to the boards, with the addition of the price placed centrally near the foot of the front panel.

The price would be moved from front to central or lower spine around 1918, and from spine to front flap in the early 1930s.

The US writer G. Thomas Tanselle has published a very comprehensive survey of the history and significance of the dustjacket.  The webpage offers a link to a copy in PDF form, which is highly recommended.

The Times Literary Supplement has an 
article by James Fergusson on the importance of the dustjacket.

The Bodleian Library has an article on the earliest known example of the dustjacket.