Swimming: Parents, but moreso the teachers in the swimming classes they arranged, and primarily my teachers at school. Age: not certain, I remember having classes around the age of 5-6 or so.

Riding a bike: Parents, mainly Dad, around the age of 6.

Reading: Again, my parents were primarily responsible for this, and they encouraged it greatly from a very early age. I was probably beginning to pick up the basics sometime after my 4th birthday, and I could handle simple books before I turned 6. I was the top speller in the school during my final year of primary school.

I can't be certain of the ages quoted here; they're merely best estimates based on approximately on my earliest recollections of doing these things.