The place to go for that kind of thing is the National Archives at Kew, Surrey. This page shows the sort of information that is available there.
I thought that it would be useful to point this out as quite a lot of visitors are disappointed by the lack of personal information that we hold on the many men and women who spent their wars on the islands.
We do make up for the lack of cold, hard fact with lots of pictures of jolly parties though, look:
Navy Camp at Yesnaby, 1943.