In Episode #3 of her series How to Teach Anyone to Read and Have Fun While Doing It, Dr. Jill Allor describes how to teach letter sounds.
PDF of Slides
Links Mentioned in this video:
UFLI Blendable Sounds: A Quick Review (Dr. Holly Lane)
Dr. Tim Shanahan blog on letter names and sounds/research https://shanahanonliteracy.com/blog/letter-names-or-sounds-first-you-might-be-surprised-by-the-answer
Teaching Word Recognition by Dr. Rollanda O'Connor https://www.guilford.com/books/Teaching-Word-Recognition/Rollanda-O'Connor/9781462516193