All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.
We have already answered some of your questions in previous Fataawa. Firstly, please refer to Fatwa 82688 to know how to seek knowledge. Secondly, for the best books which one should get, please refer to Fataawa 84508 and 87237. Thirdly, to know the most important compilations of Hadeeth, please refer to Fatwa 82311. Fourthly, we have previously introduced the major six books of Hadeeth in Fatwa 87493. We also introduced the books of Al-Bukhari and Muslim in Fatwa 86172.
As for the book of Ad-Daarimi, it is one of the reliable books on Prophetic narrations, it is called "Sunnan Ad-Daarimi", and its author is 'Abdullaah Ibn 'Abdur-Rahmaan Ad-Daarimi, who died in year 255 A.H. This book is a reliable book but this does not mean that all its narrations are authentic, rather it includes some unauthentic narrations, because its author did not stipulate in his compilation the narration of authentic Hadeeth. Moreover, this book is classified according to the Fiqh topics and chapters. The last topic in this book is "The Excellence of the Quran" in which he mentioned many narrations on the virtue of some verses and chapters of the Quran, and the etiquettes of reciting the Quran. However, some of the narrations which were reported therein were authentic and some were not. Most of the compilations of Hadeeth dealt with this subject (the excellence of the Quran), like the books of Al-Bukhari and Muslim which included many authentic narrations on this topic. As a matter of fact, Al-Bukhari mentioned some of these narrations under two topics "At-Tafseer" and "The Etiquettes of the Quran."
As for the books of the biography of As-Sahaabah (the companions) including the rightly guided caliphs, they are plenty in number; the most comprehensive of which is the book entitled "Al-Isaabah Fi Tamyeez As-Sahaabah" written by Ibn Hajar . He compiled it from the books of Prophetic narrations, history books, the books of the biography of the companions such as 'As-Sahaabah' of Abu Nu'aym and the book of Al-Istee'aab by Ibn 'Abdul-Barr and other books. Finally, there is a book on the same subject for As-Sayooti entitled "The History of the Caliphs".
Allaah Knows best.