Looking for a full-length biography of someone? Do a "Browse" search in The Catalog using the person's name (last name, first name) as your search term.
A scholarly biography will often give you information on primary sources (collections of papers, official documents, etc.) that may be available on that individual. So check the bibliography and notes!
If you're looking for works for which that person is responsible for most of the content (an autobiography; photographs; news reports; etc.) do a "Browse" search as above, but now select "AUTHOR" from the pull-down menu.