Children with cognitive deficits tend to have learning that is slower paced, more generalized than detailed and may or may not have deficits in core areas of skill attainment. These may include delays with short or long term memory, visual motor development or planning, visual-perceptual skills, numerical or language concept attainment and social-emotional development (to name a few).
An excellent resource is the National Association for School Psychologists website (parent or consumer pages) http://www.NASPonline.org
Also, the Association for Retarded Citizens may prove helpful. (There are numerous websites for this group)