'Virtual Jamestown' makes an extensive collection of early Virginia documents available at this site. These include the Lawes Divine, Morall and Martiall, John Smith's works, and several period accounts of Jamestown. The site posts documents pertaining to Bacon's Rebellion.
John Smith's 1616 Letter to Queen Anne describes Pocahontas.
A handful of documents relating to colonial Virginia, including charters of the Virginia Company, can be found at Yale University's Avalon Project.