Type in keywords to describe your subject. For instance, if you are looking for resources on war and religion type in war religion.
Filter your results by using the options on the left toolbar to narrow your results. You can filter by format (such as books or articles), author, creation date, availability online, etc.
When searching for a specific book use quotations around the first few words of the title, for example, "encyclopedia of religion and war". Use the other options to narrow down your results if desired.