Sir Walter Ralegh’s Discoverie of Guiana, ed. Joyce Lorimer, Ashgate Publishing Company for The Hakluyt Society, 2006.
The Letters of Sir Walter Ralegh, eds. Agnes Latham and Joyce Youings, University of Exeter Press, 1999.
The Poems of Sir Walter Ralegh: A Historical Edition, ed. Michael Rudick, Arizona Center for Medieval and Renaissance Studies in conjunction with the Renaissance English Text Society, 1999.
Ralegh’s Last Voyage, ed. V.T. Harlow, Argonaut Press, 1932 (contains many of the documents concerning the second expedition to Guiana and Ralegh’s execution.)
There are no modern editions of most of Ralegh’s prose works, not least the monumental History of the World. There is a very fine academic study of the History by Nicholas Popper: Walter Ralegh’s History of the World and the Historical Culture of the Late Renaissance, University of Chicago Press, 2012. In the British Library is Ralegh’s notebook for the History of the World, complete with beautiful hand-drawn maps, some of which you can see here: www.bl.uk/collection-items/sir-walter-raleighs-notebook-for-his-history-of-the-world
There is also no easily accessible-but-scholarly edition of Ralegh’s poetry, although many of his poems can be found online. The poet Ruth Padel offers a selection, together with some poems by Ralegh’s contemporaries, including Queen Elizabeth and the Earl of Essex, in Sir Walter Ralegh (Poet to Poet), Faber & Faber, 2010.