Lifted off Martin Doreys Twitter, hope the link works. http://www.outandaboutlive.co.uk/Motorhomes/News/General/Motorhome-friendly-parking-guide-2013/Print-_ch1_nw2531
Click on the view or download link to the Browns & Read website, then look down the bottom for the download symbol (an arrow pointing down into a short armed U to the right of the printer symbol). Choose the full download option and you should get a PDF that you can save to view later.
We found one of the motorhome spaces listed in that book for Weston Supermare when we last went in September. It was just a couple of larger spaces at the back of the pay and display car park, but they are monitored so normal cars can't use them. You should have seen the evils we got from all the car drivers circling around the car park because there were no spaces, and we just backed straight into this:
This looks useful.. http://maps.google.co.uk/maps/ms?ie=UTF8&hl=en&msa=0&msid=216846009054001719306.00049a6f26c5aca9df2a3&ll=53.722717,-3.823242&spn=8.431148,18.764648&z=6