Definitions of evidence based nursing have varied in scholarly literature. Scott & McSherry's extensive literature review looked at commonalities between EBN definitions and synthesized them to come up with the following definition:
"An ongoing process by which evidence, nursing theory, and the practitioners’ clinical expertise are critically evaluated and considered, in conjunction with patient involvement, to provide delivery of optimum nursing care for the individual."
Scott, K. & McSherry, R. "Evidence Based Nursing: clarifying the concepts for nurses in practice." Journal of Clinical Nursing 2009; 18(8): 1085-95.
From the EBN Guide, UNC Health Sciences Library; Image from: http://qsen-evidencebasedpractice.wikispaces.com/file/view/ebp.gif/220328596/246x222/ebp.gif
As professionals you will want to use bibliographic databases such as PubMed (MEDLINE) to keep current with the research literature.