Swami Sivananda put him to work in various departments of the ashram - kitchen, temple, office, typing, the press etc.
He then became the private secretary to Swami Sivananda, dealing with correspondence, typing books, etc. and generally helping in his day-to-day activities.
Swami Venkatesananda had a phenomenal memory. When Swami Sivananda went with an entourage in a special train (which covered India from north to south and east to west), Swami Venkatesananda listened to Sivananda's discourses during the day, and typed them out verbatim while sitting in the train toilet each night. These talks were published as "Swami Sivananda's All India Tour." (It is currently being reprinted in Sivananda Ashram, Rishikesh.)
Swami Venkatesananda spent seventeen years at the feet of his Master, Swami Sivananda, before commencing, at his Master's request, his mission to countries outside of India in 1961.