James Cook joined the Navy in June 1755 as an ordinary seaman, and joined His Majesty's Ship Eagle.
He then joined His Majesty's Ship Solebay as Master.
In 1758 he sailed in His Majesty's Ship Pembroke as Master from Europe to Newfoundland.
Extracts from his log, with commentary, have been published in Cook's Log.
As well as biographies of the captains he sailed under.
Some of these articles are available to be read here.