The following sources provide overviews of ideas, people, and events in European and British history. They are a quick way to find out the basic facts and current points of debate. When using an article in an encyclopedia or handbook, always check the bibliography for further reading at the end of the article. It will provide a selective list of the books, articles, and, frequently, Web resources considered to be the most up-to-date and reliable.
For background on individual countries, these histories are some starting points:
Collins, James B. The State in Early Modern France. (2009)
Lynch, John. Spain, 1516-1598: From Nation State to World Empire. (1992)
Whaley, Joachim. Germany and the Holy Roman Empire. (2012).
Doctoral students go through an exhaustive literature search when writing their dissertations. They also tend to work on new questions, sometimes ones that have received very little attention from scholars before. You can sometimes obtain these dissertations and benefit from all the bibliographic treasues and new ideas. Check Dissertations & Theses to identify dissertations on your topic.