In many of the NOVA Library databases (MEDLINE, CINAHL, Nursing Reference Center), you can can limit your search to just practice guidelines - look for a limiter called "guidelines" or "practice guidelines", often found under "Publication Types".
A number of textbooks, handbooks and databases may be consulted to effectively answer background questions. The library also has many ebook collections which you can check out on the Downloading eBooks Research Guide.
National Guidelines Clearinghouse
A public resource for evidence-based clinical practice guidelines from more than 100 institutions and organizations. It is sponsored by the Agency for Healthcare Research and Quality (AHRQ) and the U.S. Department of Health and Human Services, in partnership with the American Medical Association and the American Association of Health Plans.
Professional Organizations such as the American Heart Association, the National Cancer Institute, the American Psychiatric Association or the American Academy of Pediatrics may post relevant evidence based medicine reviews or practice guidelines based on ebm reviews on their Web sites.
At least some of these will be picked up by the National Guidelines Clearinghouse.
Some specific organizational guideline links can be found to the left, in the center column of this guide.