Where can I find a documentary history of UN human rights bodies?

The Library of the UN Office of the High Commissioner for Human Rights (OHCHR) has prepared an extensive Human Rights Timeline research guide.

From the guide description: 

The Human Rights Timeline is your guide to the history of human rights development through official documents of the United Nations:

• reports and resolutions of the Commission on Human Rights and Human Rights Council, reports of the Special Rapporteurs and Working Groups,
• resolutions of the Economic and Social Council and of the General Assembly related to human rights,
• treaties, conventions and declarations and human rights conferences.