Search on the Library Homepage allows you to search multiple Library databases at once.  Results will include books, journal articles, newspapers, theses, etc. as well as materials held in Special Collections and Museum Collections.

In the search results use the filters on the left to narrow down the results. 

Use the "Library Catalogue" filter to restrict to books etc. held in the Library, or use the "Format" filter to select e.g. journal articles, and then select the "Full-text" filter to restrict the search to items you have full-text access to.