Self study book

First of all keep in mind Importance of ICAI Study material. Study material is realy good for knowledge building and for practical work.

You can refer T N Manoharan for DT ( good from exam as well as practice point of view) and also compiled in simple language. 

Thank you So much, What about IDT???

For IDT ( GST: you can refer ICAI BGM which is compiled with real time data and with clear explanation, you may find it very lenthy but perfect one) 

Custom : I had refered banger 

Thank you so much