Dictionaries provide short definitions or terminology or a brief overview of a person. Encyclopedias contain longer essays that provide a more in-depth discussion of major topics, and sometimes references to other sources.
Useful subjects in the library catalog (be sure to use a "Subject Heading" search):
The Economist Dictionary of Business, Graham Bannock, 2002. (paper book)
Perkins/Bostock Reference HF1001 .B366 2002
In addition to definitions of terms and concepts, includes some short biographies of economists. Has a UK bias.
Longman Business English Dictionary, Longman, 2000. (paper book)
Perkins/Bostock Reference HF1001 .L664 2000
This dictionary includes 20,000 words and phrases and has pronunciation guides in addition to definitions. Includes both British and American English terms with notations to distinguish them.
Understanding American Business Jargon: A Dictionary, W. Davis Folsom, Greenwood Press, 2nd ed., 2005. (paper book)
Perkins/Bostock Reference HF1001 .F65 2005
Geared toward the clarification of jargon and popular business metaphors This dictionary might be especially useful for non-Americans and/or non-native speakers of English. 1997 edition is online.