Hi Ben, how are you getting on with training/the application process?
As you mention September 2009 I presume you're going for Officer entry? Just want to confirm that's the case. What are your A level grades going to be like? There's been a change to the qualification requirements recently and it's worth considering whether you're up to the standard. Bear in mind that nearly all the applicants are graduates, I was told by a careers advisor that if your grades are even slightly border lining the minimum you can expect to be ripped apart by the Admiralty Interview Board. I'm not trying to scare you/get you down, I'm just repeating what I've been told.
As for training advice, the training tool is very helpful although most of it is common sense/knowledge it's nice to have it in a structured form. What's helped me most is simply banging out a few press ups every now and again - for instance every time I go down or up the stairs or to the bathroom I'll do a set. I started out being really pathetically weak at press ups, now I am far better. The initial rate of improvement will be huge, just make sure you're eating correctly and increasing the work load with your progress and you should keep improving at that rate.
Last bit of advice, make sure you are doing the exercises exactly how how instructed by the training tool. Press ups with the elbows tucked in target different muscles to other types, so make sure you have trained using the correct technique or you'll be wasting your time. Moreover, if your technique is a barrel of **** at Lympstone they'll deduct from your score quite severely.