the problem with trying to "figure" it all out here is that there are so many different types of schools:
1) international
2) ESF
3) DSS (direct subsidy scheme) local but "better"
4) local, chinese & english medium of instruction
locals here tend to put their child into nursery anywhere from 2-2yr8 months. that is usually called N1. Once the childr gets to 3yr8m, then they are in K1; K2 (4yr8m); K3 (5yr8m). local primary schools do not take children before they reach the age of 6.
ESF schools generally have K1 & K2, then at the age of 5, they go into P1(primary 1).
so, for example: my son was born in Feb 2005.
because he misses the cut-off day of Dec 31, he must wait another year before he can go into primary school.
if he was to go to ESF, he would start P1 this coming september(2010). but, we have decided to put him into a local school so that he learns chinese. because of that, he will instead do K3 in september 2010 and start P1 in september 2011.
international schools are VERY VERY VERY expensive (doesn't matter what visa you are on).
ESF schools, for us, are still expensive. they are not as bad as the int'l ones, but still, we can't afford $5-6k/month on school for each child.
local schools: some are free, some charge fees, some are expensive. it all depends on the school you are interested in.
if you want an int'l school: WAITING LISTS! you should start contacting them NOW to see what their policies are.
most schools that teach using english, will have mandarin as the second language, not cantonese. if you want your child to speak cantonese (and read & write) they MUST go to a local chinese-medium school. (this is what we've decided to do, at least for the first few years to see how our kids fare).