The main sources I have used for the history of ancient China are:
Hucker, C.O., China’s Imperial Past, Stanford, 1975 – the most informative of the books I have used, and very readable.
Roberts, J.A.G., The Complete History of China, Sutton, 2004 – also a very good introduction, and also highly readable.
Eberhard, W., A History of China, Routledge & Kegan Paul, 1977 – very useful to be read in conjunction with other general histories, but to be used with caution – it embodies some sociological models which have been ditched in recent years.
An even older book, but enormously informative and insightful, is Fitzgeralsd, C.P., China: A Short Cultural History, Barrie & Jenkins, 1953 (despite the title, not that short – 624 pages).
A recent book which has been well received is Keay, J., China, A History, 2010. (I haven’t yet read this, but I have read his India, A History, which is good).
Loewe, M., Crisis and Conflict in Han China, Allen & Unwin, 1975, offers a brilliant insight into the workings of Han government.
A lavishly illustrated work on archaeology for the general reader which includes good sections on China, is Renfrew, C. (ed.), Past Worlds: The Times Atlas of Archaeology, Times Books, 1995, p. 92-3, 146-7, 190-5
A work on general archaeology aimed more at students, but eminently readable and with very useful coverage of ancient China and the roots of Chinese civilization, is Scarre, C. (ed.), The Human Past, Thames & Hudson, 2005, p. 234ff., 552ff.
If you want a quick introduction to the archaeology of ancient China, try the small but beautifully illustrated handbook by Debaine-Francfort, C., The Search for Ancient China, Thames & Hudson, 1999.
For an insightful look at government in ancient China, see Finer, S. E., The History of Government, I, Ancient Monarchies and Empires, OUP, 1999, p. 442ff.
The Ancient History Encyclopedia has a very useful series of pages on Ancient China: start at the general Ancient China page and follow the appropriate links.
The British Museum’s website Ancient China is a wonderful teaching resource.
Wikipedia’s coverage of Ancient China is as usual vast, and is particularly useful if you want to chase down a specific topic (though coverage of some topics can be a bit patchy).