All That Is Worth to Know Under Heaven
The nine years of its compilation were followed by eight more years of the preparation of six more copies by the work of almost 4000 scribes. Then the seven copies were solemnly deposited in seven special libraries throughout the country, established for the purpose with imperial decree. And this carefulness has proved really foresightful. The thereafter following two centuries of Chinese history abunded in catastrophies, upheavals, foreign and civil wars and destructions, so that only three of these copies – the Wenjinge in Hebei, the Wensunge in Shenyang, and the princeps, the Wenyuange of the Forbidden City – have been intactly preserved. It was this latter, the Wenyuange, that was first photocopied in the 1930s by the Commercial Press, then published in 1500 volumes – already in Taiwan – by the same Commercial Press in 1983-86. This rare edition was further published in Shanghai in 1987, and now scanned page by page and made available in electronic form here. Trabajo de chinos.
Recently the complete collection has been published as a full-text digital database by Digital Heritage in Hong Kong (2004) as well, but this edition, although not horribly expensive – the China Publishing House offers it for 980 USD – only can be found in a handful of libraries throughout the world. If you are responsible for acquisitions in your library, or are on good terms with one such person, do consider ordering it. And in the same thought, er, uhm... don't forget about the Studiolum CDs either.
The annotated catalogue of the Siku Quanshu, compiled by Ji Yun in 1798, and known as Siku quanshu zongmu tiyao 四庫全書總目提要 [General catalogue of the Siku quanshu, with descriptive notes] was published in Beijing as a reprint in 1965, and in a revised and enlarged edition in 1997.
A concise overview of the works included in the Siku Quanshu can be found here (in Chinese only).
The only monography on this collection available in a Western language seems to be the one by Guy, R. Kent, The Emperor's Four Treasuries: Scholars and the State in the Late Ch'ien-lung Era. Harvard: Harvard University Press, 1987.