BCC guidance on Planning Applications: your chance to have your say.
NPN guidance on sustainability issues.
Guidance on ‘how to do your own plans’
Guidance on commenting on planning applications.
A number of agencies have written guidance on aspects of planning.
Locality have drawn up guidance with The Glass-House including on responding to planning applications and how to do neighbourhood Plans.
CPRE (Campaign for protection of rural England) has guidance including on how to choose which sort of plan to do.
CABE (Commission for Architecture and the Built Environment) has guidance on many aspects of design and checklists including on Building for Life criteria which are still used; the Commission ran from 1999 to 2011.