Search Strategies - Keyword: With keyword searching, be sure to employ LIMITERS if you retrieve an unwieldy number of records. Limiters include "AND" and "NOT."
Other helpful ways to limit searches include filters or facets built into databases and catalogs, including such elements as
Search Strategies - Subject Headings: Subject headings are elements of a "controlled vocabulary," as opposed to natural language. The upside is that subject headings are carefully, specifically applied to each library resource, but the downside is that you need to know what subject headings to choose from in order to search successfully. A few pertinent examples follow.
Worldcat: The Catalog of Catalogs! A critical discovery tool! Try some of your Main Catalog searches in Worldcat.
RIBA is another great resource for British / English architecture. This catalog includes not only books in the library's collection, but also indexes journals.
Google Books: Searches the full text of books that Google scans and stores in its digital database, which Google claims holds ~7 million works.