The book I am using is "Teach your child to read in 10 minutes a day" by Sidney Ledson. It is a Canadian author. But I think you misread my message - I said that we are focusing on the "Sounds" NOT the "Names". Echo happens to know the names of a few letters, but not by any teaching on my part. When she asked for an "Ahh", that would be because that is how she knows the letter A. Not by name, but by the short ahh sound that A makes. That was from my teaching.
Echo knows the sounds (short sounds for vowels) for U, P, C, A, T, th (as in the), e (as in the), H, O, and G. She can figure out about 25 different 3 letter words from those letters.
Delta knows the above, plus B, I, R, N, S, D, E - and can figure out about 100ish 3 or 4 letter words. He has just started working on sentences using mostly the words he already knows... He has read 4 or 5 of the first sentences that this book uses. He is also enjoying seeing words he knows in "Hop on Pop".... The book I'm using slowly introduces the other letter sounds, plus some of the different sounds and combination sounds during the sentence work.
The book uses ONLY capital letters at this point (after the first 15 sentences, it introduces lower case) - but Delta seems to have no problem recognizing a letter in its upper and lower case forms.
I have heard a lot of people mention "Teach your child to read in 100 easy lessons", but have never seen it myself....