Application Timelines, UK

This is the application timeline for UCAS, for the year 2009. Note the early deadline for Oxbridge. Also, the respective schools will have their own deadlines as the teachers need time to write their reports. Very roughly, August will be the critical month for applications for Oxbridge, and the interviews will be around late October.

Something produced by the University of Warwick, also useful.

Application Timelines, US

Application Timelines, Various Scholarships

PSC scholarship:

One can apply in September and October, before the A level results are released. In such a case, the psychometric test will be in late November or December; the interview by the panel would then be as early as the middle of January. The reply can be as quick as the next day. Should they choose to refer you to the various ministries, the respective ministry will get back to you sometime in February, informing of a tea session or sit down session sometime in March. 

That should be the application timeline for the early application.