Books and Links
http://astore.amazon.co.uk/susanwatkin
When I am in Greece I like to look for locally published books. Some national Greek publishers publish books in English. Other booklets are locally produced - such as walking guides to a particular island. You will sometimes find bookshops, or shops with a range of books, in quite small islands.
A good starting point is Frewin Poffley's Greek Island Hopping. The book is usually published on 1 January each year, so look out for the current edition.
James Theodore Bent's The Cyclades, or Life Among the Insular Greeks is excellent for a taste of what it was like to travel in the Cyclades in the 1880s. This paperback version is the best to take with you, earlier editions are now collectable and much more expensive.
The Greek publisher Melissa publish a range of books on Greek architecture. The Amazon link is the only one I could find. I suggest you look out for the slim large format volumes to one island or mainland region when you are in Greece.
And some other random suggestions