Most sites seem to be American but never the less there is some useful information here.
The Shared Parenting Information Group offers advice and support for families who are separated or divorced. I'm sure that the response would be well worth the effort. There doesn't appear to be a Web site for this UK National Group so we have included the contact information for them. To find out more about the books on this page just click on the title or cover to go straight to Amazon. Or you can check the selection of books Amazon has on offer by clicking on the Amazon Index link.