Where to look for information depends on what type of source best suits your need.
See below for links to these sources. If this feels like too much to choose from, or if you have any questions, Ask a Librarian!
eBooks: Academic Collections searches and views the full text of eBooks. This database contains a large selection of multidisciplinary eBook titles representing a broad range of academic subject matter.
What about Wikipedia? While sometimes controversial, Wikipedia entries can be great places to start - so long as you don't stop there. More information about how to use this source responsibly is under the tab for Wikipedia!?! .