An excellent introduction to Adhyasa Bhashya by Shri Saxena.
Location you could create PDF's of Shankara Bhashya
Transcript of Swami Paramarthananda's lectures on "Introduction to Brahma Sutras".
Audio of Shri Shankara's Ashyasa Bhashya (Many thanks to Sunderji!).
Lectures (PDF link) of Shri (Dr.) Mani Dravid Sastri. More lectures are these (all PDF links): 1, 2, 3, 4.
From advaitin files.