I've gathered here a handful of resources from internet to get you started. Here are some poems, articles, and interviews.
If you are looking for a good book of poems to start with, I have to recommend the selected volume The Moon Disposes from 1987, which was also published as Peter Redgrove: Poems 1954 - 1987 in the Penguin International Poets Series. It's one of a handful of books I often carry with me, and that I rarely, if ever, put back on the shelf. If you've never read Peter Redgrove before, I hope this round-up serves to ignite your interest in reading more of his work.
"The Count of Some Account"
from "Feeding Pieces"
"More Than Meets The Eye"
"The Patient Successor"
"The Visible Baby" (with commentary by Ruth Padel)
"Water-Witch, Wood-Witch, Wine-Witch"
"Woman in a Flowered Dress"
ESSAYS & ARTICLES
Scientist into Poet: The Emergence of Peter Redgrove
an article by Neil Roberts from The Wolf magazine.
Peter Redgrove's "Tapestry Moths"
an analysis by Jo Furber from The Argotist
The Peter Redgrove Library
an article by Michael Peverett from "Intercapillary Space"
The Mystical Barber: A Review of The Harper
a review of Redgrove's posthumous miscellany by Anthony Thwaite
The Science of The Subjective: An Interview with Peter Redgrove
by Neil Roberts
An Interview with Redgrove
by Lidia Vianu
An Obituary for Peter Redgrove
from The Telegraph
A Remembrance of Peter Redgrove
from the University of Leeds
Peter Redgrove's Papers
Redgrove's papers are housed in the University of Sheffield.