S.H.
In my daughter's school, for Kindergarten and 1st Grade, they are taught "sight words." Each level of words, being per their age/grade.
It is called "Dolch Sight Words."
This is what schools use.
Here are some links for it:
http://www.learningbooks.net/xLPDolch.html
http://www.mrsperkins.com/dolch.htm
http://www.quiz-tree.com/Sight-Words_main.html
http://www.msrossbec.com/sightwords.shtml
to work on words with him... don't overwhelm him.
Just work on a 'list' of about 5-8 words. It also takes repetition and then practicing 'reading' something with those words.
It is also part phonics... sounding out the words, and memorization. "Remembering" sounds and how a word is read.
It takes consistency... and working on a particular set of words, repeatedly until he "masters" it. THEN when he masters a set or words, then, go on to another set of words. Gradually building up... from there.
I would ALSO, use a marble composition book... and per alphabetizing it and the pages... write words in there that he masters... for each alphabet... thereby, he will be making his own "dictionary" of words that he knows. It provides incentive and a reference for him to easily look through, as he learns more words.
THAT is what my daughter's Teacher's did. Each kid, had their OWN "dictionary" of words, that they wrote into their composition tablet. And then that way, the words are all organized into ONE tablet for easy reference... versus having to try and remember everything and the words being scattered all over the place or you forgetting which flashcard word he knows or not and having to keep track of it mentally.
AND, by having him write his mastered words into the tablet, he will also get added practice of how to 'spell' it.
all the best,
Susan