Where can one find authentic sources of information about the first 5 Khalifas along with references? Also, in general where should one look for books on Islamic history which have references in them?

The question is very vast and general therefore, cannot be answered precisely.

If you are looking for a book which gives you references of every single event, statement, incident, and claim and is based on absolutely 100 percent authentic information as well then you will not find any such book in English. In fact, you will not find such a book even in Arabic or any other language of the world on the political, social and religious history of Islam. This is simply due to the nature of the subject. We are talking about centuries of information.

If you want to read a book which gives references to some extent then you may read the books of Dr. Ali M. Sallabi. He is a contemporary writer and I think for your undergrad studies of Islamic History, this is the best option you have. His books are quite famous these days, so you can find them in almost every part of the world.

Among the famous medieval works on history and geography are those of Ibn Athir, Baladhuri, Tabari, Suyuti, Ibn Khallikan, Abul Fida, Masudi, Ibn Khurdabih, etc.

(Answered By: Brother Hunain Aijaz  source :http://blog.islamiconlineuniversity.com/question/authentic-books-on-islamic-history-with-references/)