See the following for the lists of UK Post Offices compiled by Ken Smith.
The files are stored as PDF files, so you need Adobe Reader installed to view them. Internet Explorer can give problems viewing PDF files if you are running a 64-bit computer, as the Adobe reader is only 32-bit (symptom is that you just get a blank screen when trying to view a link). This is because Internet Explorer refuses to use the 32-bit reader unless the "Enable Protected Mode" checkbox in the Tools-Internet Options-Security tab is deselected. If you deselect this checkbox it will warn that this puts your computer at risk - if this concerns you then either download the files to your hard drive and view them from there (right click and select "Save Target as ..." or "Save Link as ...") or use a different browser (Firefox and Chrome work OK).