This is a great site:
Emily Dickinson Archive makes high-resolution images of Dickinson’s surviving manuscripts available in open access, and provides readers with a website through which they can view images of manuscripts held in multiple libraries and archives. This first phase of the EDA includes images for the corpus of poems identified in The Poems of Emily Dickinson: Variorum Edition, edited by R. W. Franklin (Cambridge: Belknap Press of the Harvard University Press, 1998).
I don’t know what I can add to that; if you’re a Dickinson fan, you’ve wanted something like this for a long time. If I weren’t editing a bear of a job, I’d be spending a lot of time there. (Via MetaFilter, where you will find more links.)