Getting started with online historical research

First off, it's official that I'm a PhD and I have a two year fellowship at the USDA's Climate Change Program Office! I'm moving from Arizona to Virginia and I couldn't be happier.

In the course of my dissertation research I utilized many online databases and archives. Some of these were through my library, so they required a university login and password, but many are freely available to anyone. I thought I'd list some of these resources.

Universally helpful:

• Google n-gram viewer. When I'm learning about a new historical topic, this is one of the first places I turn to, especially when I want to know about the etymology of a specific phrase or word. I can then click on the link to Google books from specific time frames and check out how the word is used, in what contexts, etc. 
• WorldCat.org. WorldCat is a database of virtually all published (and some unpublished) materials. While no website has a universally perfect search function, typing keywords or authors into WorldCat's search usually turns up a relevant list of publications. WorldCat is helpful because it lists the complete biographical information and what libraries hold a specific item. If it is available online, it will often link to it.
• Hathi Trust and Archive.org. These sites contain thousands of open-access digitized texts. You may have to refine your search terms to find relevant texts. (FYI "hathi" is Hindi/Urdu/Bengali for elephant, so it's pronounced with a hard aspirated "t". Listen here!)
• Google.com and Google Scholar. I'm not an expert at database querying so I spend a lot of time trying out different keywords and strings of words in Google and G-Scholar. Google often leads me to documents that I wouldn't have been able to find even within an institution's website. For example I find a lot of documents scanned and uploaded on USAID's website (because USAID funded many of the projects I studied), but there was not a good way to access these through USAID and there is no hierarchy or organization of the information, so it's just random.

International agricultural research history:

• CIMMYT Repository and University of Florida Digital Collections. CIMMYT's repository has been organized by topic, the link provided is for "wheat" but there is a sidebar on the left titled "Collections." In this case I sorted the repository by year. This repository contains published materials as well as a large amount of published and unpublished CIMMYT reports and conferences. UF's Digital Collections has a repository called "International Farming Systems" that is a collection of materials donated by Peter Hildebrand, an agricultural economist. I'm not sure what his professional affiliations were, but this repository has over 2000 international agricultural reports, some in English and some in Spanish, from roughly the 1950s onwards.
• University of Minnesota Library's digital collections. There is a large amount of scanned materials deposited here. The green revolution collection (no link, just cntl-F it on the homepage) hosts correspondences, diary notes, and biographical details of Norman Borlaug, John Gibler, and Elvin Stakman among others. It takes a while to load each scanned page, but if you're interested in finding the "raw" archival data, this is it. Borlaug's oral history is included here, so if you can't make it to the Rockefeller Archive Center but still want to read it, find it here!

Foreign policy history, Cold War era-specific:

• US State Department Historical Documents. This repository spans from 1945 to 1980 and the archivists here have helpfully separated various documents (memo's, correspondence, etc.) by date, topic, and region. All materials are transcribed so it is easy to read and to copy-paste exact quotes.
• Harry S. Truman Library & Museum. I haven't browsed this fully, but it has a collection of digital material from Truman and his cabinet, advisors, and other policy-related people. It has a large collection of oral histories.