Hi Abhay

0)Oracle tuning 101 by keerti deshpande and gaja vaidyanatha

1)Guy Harrison who comes at the top of my mind

2)Mark Gurry is obviosly the second choice

3)Tom Kyte he is also very good

4)Don Burelson

5)Ahmed Almori Unix specific

also i kniow of christopher long here at www.dbasupport.com who was supposed to write a book..dont know wheather it is out

regards
Hrishy