From GPG

Rights of Way Review Committee

The Rights of Way Review Committee (RWRC) has written a series of advisory Practice Guidance Notes (PGNs) to offer practical guidance on aspects of rights of way legislation and to recommend working practices that will enhance the overall protection and good management of the rights of way network. The intended users are local authority rights of way officers, legal officers and administrators who deal with rights of way issues on a day-to-day basis. They are also useful for land owners and occupiers and user groups.

RWRC Practice Guidance Notes has links to the documents.

Planning Inspectorate

The Planning Inspectorate issues Advice Notes (AN1 to ~ AN21) relating to procedure for determination of opposed orders, interpretation of evidence, advice to inspectors, etc. They can be downloaded as pdfs from its website which has several categories of documents; at the time of writing you need to scroll down the page to Advice Notes.