Tips on Doing and Writing Research (for undergrads and masters):
The Craft of Research, Fourth Edition (Chicago Guides to Writing, Editing, and Publishing)
By Gregory G. Colomb, William T. FitzGerald, Joseph M. Williams, Wayne C. Booth, Joseph Bizup
A Manual for Writers of Research Papers, Theses, and Dissertations, Seventh Edition: Chicago Style for Students and Researchers (Chicago Guides to Writing, Editing, and Publishing)
By Wayne C. Booth, Gregory G. Colomb, Joseph M. Williams
Books on General Public Policy:
Inventing Future Cities
By Michael Batty
The Smart Enough City
By Ben Green
The Book of Why: The New Science of Cause and Effect
By Dana Mackenzie & Judea Pearl
Kicking Away The Ladder
By Ha-Joon Chang
The Public Policy Theory Primer
By Kevin B. Smith & Christopher Larimer
More to recommend.....
Books on International Relations and History:
The Clash of Civilizations and the Remaking of World Order
By Samuel P. Huntington
Why Nations Fail: The Origins of Power, Prosperity, and Poverty
By Daron Acemoglu & James A. Robinson
The Pursuit of Power: Europe 1815-1914
By Richard J. Evans
The Utility of Force
By Rupert Smith
The Future of War: A History
By Lawrence Freedman
Technology and War: From 2000 B.C. to the Present
By Martin Van Creveld
Forgotten Ally: China's World War II, 1937-1945
By Rana Mitter
More to recommend.....