If you are going to pick a reference book to make ur study notes, then i would say V.K. Singhania (Taxmann Publication). . . But if u r thinking of studying directly from the book, i would refer T.N. Manoharan (Snowwhite Publication). . Since Singhania is very detailed, it is not suitable for quick revision during exams.
For in depth understanding refer TN MANOHARAN'S IT Text Book from SNOW WHITE PUBLICATIONS.Its seems the book is voluminous, but its not so if u understand and read, it actually requires atleast 2 times conceptual reading for better understanding. OR Else go for PADUKAS text book, the language is easy and problems are provided for each and every Theory Explianation.