You have several choices in finding academic journals:
Individual databases (easier to sort through-- if you have a good sense of your topic, go to one or all of these):
If you want to browse for books on the 4th floor of the library, check out this list of where you can find the subject of your choice.
When you find a book in the catalog that you want to get your hands on, note:
Once you have that information in hand, find the book on the shelf.
If you haven't found a book in an academic library before, take a look at this guide to the Library of Congress Classification System (what we use to organize our books) before venturing upstairs. Be patient with yourself-- it's a little bit tricky to use this system at first if you're not used to it.
Still not finding the book? Ask one of the reference librarians.