Peter K Steinberg is recording his experiences of working with the Plath archive at Smith on the blog - http://sylviaplathinfo.blogspot.com/
The posts include images, description of items in the archive, the general feeling of working with the papers, information about places she visited in the area and demonstrations of her typewriter etc.
Update from the Plath archive: Day 1
Recording his initial searches
Update from the Plath archive: Day 2
Including transcribing Plath's letters and and image of a greetings card in the collection
Update from the Plath archive: Day 3
A tour (with photos) of some of the places Plath visited and an image of her prom dress which is in the Smith collection
Update from the Plath archive: Day 4
Including a video of Peter typing on Plath's Royal typewriter.
See also Peter's records of his time at the Lilly Library, Indiana - Day 1, Day 2, Day 3, Day 4, Day 5