Tuhfah As-Saniyyah (a rather popular explanation of Al-Ajuroomiyyah).  The author is Muhammad Muhy Ad-Deen `Abd Al-Hameed. This book contains charts and has been checked by Ubaayd Rabih As-Shaanqitee (Haafidhullaah ta'alaa) and his book is the best explanation of al-Ajuroomiyyah I have yet to see.  However it isn’t the most basic, which is why you find that this explanation itself, has been ‘explained’. Printed by Mu'assatur Risalaah (Beirut) printed on yellow paper 300 pages.