Google Photographic Books on the Web.
Whilst browsing through all the Google Resources I came across Google Books.
There seems to be a huge resource of books on the subject of photography and related topics.
Now it seems that some of these are incomplete with pages or sections missing, nevertheless there is still a decent amount of reading material included. if a particular book takes your fancy then you can go out and buy it. Consider this a s a sort of previewing that you would do on a wet Saturday afternoon in a big city centre bookshop.
Below are a number of links to some which I have bookmarked.