According to me,Suresh Raina scored a century in his debut test match.
Sachin tendulkar has scored the most test centuries. 41 in 156 matches for India.
Charles Bennerman of Australia scored the first century in the first inning of the first Test Match in 1877.
Brian Lara West Indies
The first Pakistani cricketer to score a century on his debut in Test cricket was Khalid Ibadulla, who scored an innings of 166 against Australia in October 1964. Ibadulla, who had an eighteen-year first class career with Warwickshire, had just two other scores in double figures in a four-match, eight-inning career in Test cricket.
Don Bradman,he could have had the average of hundred if he would have scored 4 more runs.
i think it was Brian Lara's 400in a test match
Adam Gilchrist (100).