Although a guidebook is always welcomed with a new deck, one is not needed when the deck follows so closely to the Rider-Waite-Smith system as does The Mitchell Tarot. If you are familiar with the system, you can see from the above images that the deck will be easy to follow.
As stated above, there isn't a guide book available at this time, but for some thoughts on the deck's creation, example interpretations, and suggested spreads visit Mitchell’s site - https://www.life-plan-blog.com/mitchell-tarot/
Grab a copy of The Mitchell Tarot at Making Playing Cards.
To purchase other decks by the author visit - https://www.makeplayingcards.com/sell/jameshimm