Best book for GST

As far as I know the websites like ca club clear tax have full bare facts with latest ammendment notifications and faqs I have used clear tax website

You can refer the Background Materials on GST issued by the Indirect Tax Committee of the Institute of Chartered Accountants of India ( ICAI ). It is available on their website for free of cost. You just have to fillup a simple form to Download the same.

You can also refer CA Bimal Jain Sir's book on GST - "GST Law and Commentary 6th edition". It will be available in the market within September end or 1st week of October 2020.

Regards,
Shivam RC.