If you need help learning how to search, including how to choose good search terms, go here and scroll down to the links under HOW TO SEARCH THE INTERNET:
My favorite way to search is to go to Google's advanced search page http://www.google.com/advanced_search?hl=en and put my search words or phrases into the first or second search box (either "all the words" or "exact phrase"). However, there many other strategies for searching you can use, and the HOW TO SEARCH THE INTERNET section will help you best.
Learning to use Google or other search engines can save you time and help you learn to find information efficiently. Here are some websites that can teach you how:
... and one to help you judge whether a particular website's information is worth your time:
This site has dozens of links to information about WWII and the Holocaust.