Reviewers on VAK1969 note that Varma uses an accessible, sometimes anecdotal style that makes dense philosophical concepts like Maya (illusion) and Brahman (ultimate reality) easier to understand.
If you are looking for Shankara’s actual writings ( Bhashyas or commentaries), these are the standard texts often sought for study: shankarachari kniga skachat
The most acclaimed modern biography and philosophical review for download is by Pavan K. Varma. Review of " Adi Shankaracharya: Hinduism's Greatest Thinker " Reviewers on VAK1969 note that Varma uses an