Centre for Clinical Interventions. This has very detailed self-help information. The guides in the Resources section teach you CBT to help with problems including depression, panic attacks, worries, procrastination and low self-esteem.
MoodGym. This is an interactive web program designed to prevent depression. It consists of five modules, an interactive game, anxiety and depression assessments, downloadable relaxation audio, a workbook and feedback assessment. You have to register to use the site, but it is free.
Wellbeing Glasgow. This is a useful website that provides information on common problems and how to tackle them. There are also lots of assessment questions if you are not sure what the problem might be, as well as videos and audios.