Books & Advice for Lower-end Consulting Firms (UK)

Hi everyone,

I've been lurking on these forums for quite some time now, and today I've finally had cause to ask you all for some crucial advice. I am a master's student studying a relatively 'soft' social science subject at UCL after obtaining a first class degree in economics at a similarly esteemed university in the UK (think St Andrews, UCL, Imperial, Warwick). Although I have no business-related work experience to date, I have been gravitating towards applying to some of the lower-tier consulting firms in London (Accenture, EY, etc.).

My main concern is that I have absolutely no knowledge of business structure, or even of basic accounting. I have consistently been told that extensive business knowledge isn't a prerequisite, but I'm honestly freaking out about my lack of knowledge. I'm not even thinking of applying to MBB or Deloitte (or even Oliver Wyman) precisely because of this insecurity.

My questions are:
(1) Do you guys have any recommended books that I could read - or just tips in general - that would allow me to acquire the basic (and I really do mean basic) skills needed to crack the case studies? I've already picked up 'The McKinsey Way' and 'Case in Point'.
(2) Given my background, would you guys advise me to apply to regional offices (primarily Glasgow + Edinburgh) in addition to London in order to maximise my chances of getting somewhere?

My CV is far from spectacular; I've done a stint volunteering in the third world in addition to publishing an academic paper on counter-terrorism. However, my only internship was back at the end of second year (over 2 years ago) with a small newspaper in New York. I know I've been extremely lacklustre; I've been beating myself up about it for quite a while now.

Sorry for the rant above. I'd appreciate (brutally) honest, yet constructive advice. Thank you all for your time.