Mr Paul said the ministerial appointment, until 2012, was "an honour and a privilege", which also reflected positively on the Otago Museum.
The Alexander Turnbull collections comprise part of the overall collections of the National Library of New Zealand.
Archives New Zealand's Wellington repository will, from early next year, temporarily house most of the Turnbull's extensive manuscript collections during the National Library's planned $52 million redevelopment.
The redevelopment will address critical issues with failing plant and infrastructure as well as collection storage.
Mr Paul said he was not taking his new duties lightly, knowing that the chairmanship involved taking further responsibilities.
He noted that library redevelopment was planned, and that he had been closely involved with the successful redevelopment of the Otago Museum.
He had earlier served for five years as a trustee of the National Library.
The Guardians body reports to Nathan Guy, the Minister Responsible for the National Library, and meets at the National Library in Wellington at least three times a year.
Mr Paul and an Auckland University historian, Prof Raewyn Dalziel, have been newly appointed to the five-strong advisory body, with Dr Monty Soutar and Prof Mark Apperley reappointed for further terms, also until 2012.
Elizabeth Caffin's term continues until next September.
