My oldest (profoundly-gifted IQ) didn't read till she was almost 6, that I knew of.
My next dd: we were at a girl's 3rd birthday party. The girl received several books. My dd (had turned 3 two months prior) picked up one of the books, and began reading it. I have no idea when/how she learned to read. We did not have that book at home. I didn't even read to dd particularly often. I did notice the moms in a cluster casting rather dirty looks, but the dads....the Dads spent the next half-hour bringing dd more books, and having her read them. They were absolutely fascinated. It was really funny.
My ds, we don't know when/how he learned to read, either. He was 5, when one day I walked down the hall. There he was, on his bed, reading himself a book quietly (whispering the words). I RARELY read to him, and he had not been to Kindergarten yet.
Youngest dd is 5 this summer. She can't read, that I know of -- but my kids tend to NOT TELL ME when they can read,lol. I think that you can "teach" kids to read till the cows come home, but like riding a bike, it is something that "clicks" into place. One day, they "get it."
I DO know that my brother, sister, and I all read (for real) before Kindergarten. My dad, mom, grandma, etc were all voracious readers.
Beth