One of the goals of NSG 400 is to discover and explore variations in the meaning/definition, scope and use of a given nursing-related concept, depending on the disciplinary context or perspective (e.g. whether philosophical, cultural, professional, geographical, language-related, or related to a particular patient group or practice setting).
The background sources linked below are very well-suited for these purposes. They also provide you with useful keywords--including any technical or discipline-specific terminology that you can incorporate into your database searches when you start looking for articles.
Each of the three background sources: Credo, Gale and Sage, are cross-searchable multi-disciplinary collections of encyclopedias, dictionaries, handbooks, and other reference works. They make it easy to find--as well as save and cite--useful definitions, explanations and overviews relating to your nursing concept (search using single words or very short phrases to find useful overviews, definitions and explanations).
In addition to all the materials you can find through Credo, Gale & Sage, here's a selection of more subject-specific and clinically-related background information resources: