ds1 (3.5) is "ready" to learn to read. He's using his knowledge of letter sounds and blending them together to "decode" cvc (consonant/vowel/consonant) words eg cat, pig, mat etc, and is identifying words around him eg wipes, nappies, biscuit, sausages, using his knowledge of letter/sound correspondence and semantics. The semantics bit is part of the process our brains use to decode words - this is a pack of wipes, I can see a word beginning with "w" which is the first sound in the word wipes, the last letter in the word is "s", I know what sound that makes, I guess the word must be wipes.
The teacher in me (who WAS taught how to teach children to read ) is itching to do it, but I have decided not to.
School for very young children is SO formalised now that I'd rather focus on other aspects of his development at this stage and support/supplement his reading when he begins to be formally taught in reception.
So for the moment we're sticking to lots of puzzles & games, role play, construction toys, art, cooking, listening games etc.
There's so little time left for these things in school now, we're "making hay while the sun shines".