Before the course I skimmed through the book What are Archives: Cultural and Theoretical Perspectives edited by Louise Craven, 2008. I thought it was very up-to-date and the short chapters were easy to read. If you think the whole book is too big, I suggest the first chapter by Louise Craven, From the Archivist's Cardigan to the Very Dead Sheep: What are Archives? What are Archivists? What do They Do? You can't deny that the title is thought provoking!
I also think that having a look at the Archives for 21st Century is a good tip for you to have an idea what TNA is up to!
Best of luck for thoses starting out and see you at UCL (for those starting the course there) in September, if not before !
Try: Yesterday, Today and Tommorrow, Are Records Ever Actual, or Evidence of Me.
I'd always advise doing a bit of reading before you start if you can - you don't have to be a walking encyclopaedia, but it might get you a bit ahead on your weekly workload and will boost your confidence no end.
I went to Glasgow, if anyone wants to contact me for any advice.