General information on OCD
Royal College of Psychiatrists information on OCD.
NHS inform self-help guide for mild-to-moderate OCD, based on CBT principles.
Treatment guidelines
Although NICE haven't updated the guidelines for some time, they conducted an evidence update: Obsessive-compulsive disorder: Evidence Update September 2013 (NICE, 2013) [This opens a PDF from from NICE website]
Charities and support organisations
"The national OCD charity, run by and for people with lived experience of OCD". OCD-UK is active throughout the UK and has useful information on accessing NHS treatment for OCD in Scotland.
One of the largest OCD charities in the UK. It also provides support for Body Dysmorphic Disorder (BDD). It has independent support groups in Inverness (BDD), Perth (OCD), Glasgow (OCD), and Edinburgh (OCD and BDD).
A UK charity covering all anxiety disorders, but it has information and support for OCD.