To give you an idea, my timeline was as follows:
12/12/2005 - Application submitted
19/12/2005 - Notification that my application would be delayed due to verification of my eyesight results
20/12/2005 - Invitation to take the online numerical tests
30/12/2005 - Invitation to attend the initial selection day
24/01/2006 - Initial selection day
27/03/2006 - Final Interview day
Now please bear in mind that there are several factors that delayed this; If you dont wear glasses then you wont get delayed by them having to verify your eyesight. Also, I was a little slow with all this - if you take to online test immediately and select the earliest possible dates you could get through even faster then this. Bear in mind that I left a fair amount of time between my interview days to allow for time to prepare and study.
And by the way, good luck!!