National Autistic Society - a Leading charity supporting people with autism / Asperger's Syndrome
Royal College of Psychiatrists - Mental Health Information relating to different disorders, treatment options and medication information.
National Institute of Clinical Excellence - Treatment Guidelines applicable in the UK for various medical conditions.
Young Minds - excellent charity doing pioneering work to better care provision for children and families.
NHS Choice Medicines Page - use the search box and get to information about any medication you may be interested in.