Each study offers a comprehensive description and analysis of the country or region's historical setting, geography, society, economy, political system, and foreign policy.
BBC News: Iran Country Profile--Includes a timeline of country history
Encyclopaedia Iranica - The scope of the encyclopedia goes beyond Iran and encompasses other geographical areas where Iranian languages dominated in certain times.
Encyclopedia of Islam and the Muslim World - Coverage includes key political and religious figures; geographic areas; and broader issues such as gender, globalization, reform, and terrorism with an emphasis on topics that are "perennially pertinent" to the Islamic worlds.
The Oxford Handbook of Iranian History - Explores aspects of daily life in Iran since the 1978-79 revolution that overthrew the US-installed dictator. Among specific topics are armed and security forces, Ruhollah Khomeini, the petroleum industry, relations with the Arab world, Islamic socialism, tribes, and the status of women.
Covers many broad topics by providing general background information. It includes a mindmap feature that could help you narrow down your topic or make you aware of names of people, events, or time frames to use in your searches.