I recently posted a couple of links to issuu, a self-publishing website, which allows you to publish your own books online. It looks like an excellent site, with a 'turning the pages' style interface for your books - as in my own effort below:
It is very simple to use - you just upload a pdf of your book. However, you will have to keep your own counsel about any copyright implications.
On a similar theme, there is lulu - which allows you to publish and sell books - either as a PDF or in print.
One book for sale on lulu is mentioned in the Focal Encyclopedia of Photography, 4th ed (page 336), highlighting its innovative approach to documentary: Frank Cost's, Twenty two seconds in Chennai.
Writing in the Encyclopedia, Owen Butler comments that:
"The book captures a 22-second burst of picture-making that resulted in a 75-page plus soft-cover book available at www.LULU.com. Each frame in this book is literally only what the camera was capable of seeing and not necessarily what the photographer was capable of seeing at the moment."
Self-published books of a higher order will no doubt be on display (and available for purchase) at the 'Self Publish, Be Happy' event at the Photographers' gallery this weekend. This is organised by Bruno Ceschel, a visiting lecturer at the University of Westminster.