Reddit mentions of Empires in World History: Power and the Politics of Difference

Your best bet is to read some of the newer work in global, transnational, and comparative history, especially in relation to empire.

Buy these two books:

Jane Burbank and Frederick Cooper, Empires in World History

and

C. A. Bayly, The Birth of the Modern World (this covers 1780-1914, but trust me, you're gonna want it).

Look through their bibliographies and citations when you come across something you're interested in. Then ask again when you have ideas about more specific topic areas.

This is excellent.

http://www.amazon.com/Empires-World-History-Politics-Difference/dp/0691152365/ref=sr_1_13?ie=UTF8&qid=1373434104&sr=8-13&keywords=empires

The West: Encounters & Transformations, Combined Volume (4th Edition) by By Brian Levack, Edward Muir, and Meredith Veldman is a great book focusing on "the changing nature of the West—how the definition of the West has evolved and has been transformed throughout history". It looks at culture through beliefs, ideas, technologies, and peoples, both outside the West and within it.

Terrorism: A History by Randall Law is a great book that looks at terrorism from ancient Assyria to present (post-9/11) and discusses what is used and how/why it is used. It doesn't just focus on terror in the Middle-East, but also discusses topics including the Klu Klux Klan and Algeria (under French colonization).

Empires in World History: Power and the Politics of Difference by Jane Burbank and Frederick Cooper. The book starts with ancient Rome and China, but continues across Asia, Europe, the Americas, and Africa. This book discusses Empire, not just through the military, but through culture, economy, and religion.

A History of Russia by Nicholas V. Riasanovsky and Mark D. Steinberg is focused on Russia, but looks at the formation and continuation of Russia from its time as Kievan Rus through the Soviet Union to present. It's not just a military focus, but includes political, international, economic, social, and cultural history as well.

I'm not sure what type of history (except military in general) that you are interested in, but these books (though some are expensive) can give you a general idea of some of the major historical topics/themes/ideas. As it happens, I have all of these books and would be more than willing to give them to you. Bear in mind that I am in Canada so shipping might be an issue.