Searching major databases that index scholarly journal articles, articles in books, and conference proceedings is a great way to find published ethnographic studies. Here are a few suggestions:
Research you propose that involves extended interactions with human subjects will probably require you to follow government regulations. Those legal requirements protect the people you interview as well as the integrity of your study results. Cornell's Institutional Review Board is managed through the Office of Research Integrity and Assurance, which makes sure that such research observes the law.
University policy requires that all research that involves human participants, regardless of the source of financial support, must be reviewed and approved by the Institutional Review Board (IRB) before it can be initiated. Guiding this review process by the IRB is the application of federal and state laws and various ethical principles, particularly those articulated in the Belmont Report: (1) Respect for Persons, (2) Beneficence, and (3) Justice.