I think you’ll find a lot of different answers, I’ll share mine, with a little background.
As of today I have one avid reader (age 10 girl, reading well since age 6.5 or so), two beginning readers still sounding out about 1/2 the words in a story (age 7 boy – close to making the fluency leap, age 6 girl), one beginning reader who has picked it up being around the others (just turned 4 boy, still learning how to read long vowels). Then I’ve got two little ones age 1 and 2.
With my first there was no formal curriculum. She learned letters (what they say) and then blends (like fr, th, sh) started at age 3.5, one per week with a theme like frog for fr). She started learning long vowels and just kept plodding along until it all clicked into fluency one day. She has been a voracious reader for several years and tackles classics like Little Women easily.
With my second, a boy, he had no interest in even learning what the letters said at age 4 and 5. We used Rocket Phonics to pull him into that – it uses a lot of active, whole body games, which is just what he needed. His little sister learned her letters and their basic sounds before he did, when she was 18 months old and he was 2.5. It took her one week and we just watched the Letter Factory DVD from Leap Frog. After a while with RP we were ready to just keep reading from things like the Now I’m Reading phonics readers by Nora Gaydos, and the All About Spelling readers. We’ve also played with All About Spelling level 1 (I already had it) and he enjoys the tiles and oral spelling.
With my third, a girl, she’s always just done what her big brother did and thrived. She could use anything and learn to read I think. She turns 6 next week and we’re just now seeing a difference between the two. They’re 13 months apart and she’s not gaining fluency with words as fast as he is now.
With my fourth I’ve avoided all formal lessons and he has just picked it up by listening to the others. He can read short vowel words, blends, and is starting to pick up long vowel rules. He’ll read the level one Now I’m Reading books, the labels off the crayons, signs, boxes, anything. He spells too – keeping pace in All About Spelling Level 1 with the next two older with no trouble.
All of that to say here is what I suggest:
1. Relax.
2. Figure out what he already knows. Can he tell you what each letter says? Play games to find out.
3. After knowing what the letters say he has to learn to blend sounds together. c-a-t instead of c. a. t. Work on that step. Choose a set of phonics readers to use, and when there is a word that uses rules he doesn’t know (like the word The), mention the rule and then work on that word as a sight word.
4. We also love All About Spelling because we learn why letters say which sound. For example a vowel in the middle of a word could be long because it is in an open syllable (EX: the word open has two syllables: o and pen. o is a vowel that has nothing closing it in and making it say it’s short sound, so it says the long vowel sound instead. In the pen part of the word the e stays short because it is in a closed syllable, closed in by the letter n, so it can only say it’s short sound.)
Another thing my kids have gotten more exposure to phonics rules with are the Leap Frog dvd series that come after Letter Factory, there is The Talking Word Factory (learning to blend letters into words), Code Word Capers (long vowels with a silent e, special blends like sh, ch, th). With a visual/auditory child these can be really helpful, if that applies to your son.
Above all, daily, short practice is what helps. We don’t spend more than 10- minutes per day, more than that is overkill.