The quality of resources & specific support available is extensive, so the list below represents only a selection of organisations, both international and national:

AED 
The Academy for Eating Disorders (and in particular their excellent reading lists).

ANAD
National Association of Anorexia Nervosa & Associated Disorders.

NEDA
National Eating Disorders Association

BEDA
Binge Eating Disorder Association

B-EAT 
Beating Eating Disorders provides helplines, on-line support & UK-wide support groups.

NEDIC
The National Information Centre of Canada. Information and resources on eating disorders and weight preoccupation.

MGEDT 
Men Get Eating Disorders Too. UK charitable group raising awareness of eating disorders in men.