Muhammad Al-'Uthaimin-author
It, in spite of it’s relatively small size , does focus on the rights man has, and what obligations one is obliged to do towards His Creator, Allah , the Almighty, and towards his fellow man as well ; and introduce them properly and precisely to the Muslim readers all over the world , and also to those who are either eager to learn about essential matters in Islam , or interested to know what Islam is all about
http://www.almeshkat.net/books/archive/books/Essentialright.zip