Sorry, I should have said you can get an admission form from your LEA the year before your ds is due to start.
Have a look at your LEA's website for details (the timetable varies), where I live the forms have to be in by October but we aren't informed as to whether your dc has a place until Feb/March the following year.
Yes, he will start Sep 09 (or Jan 10 if in a two intake area). Regardless though, you apply at same time for either system. You should get an application pack very soon. Depending on which LEA you are in depends on when the pack needs to completed by - can be as early as this October.
You should start thinking about schools now, and visit some too if you are not sure.
Ds will be starting in Sept 09. Our applications have to be in by the 23rd Oct. I have filled in the applications online today (I have already seen the schools because of dd's application 2 years ago, however all the schools are having open days in the next 2-3 weeks.
So I would say you need to get a bit of a move on!