In this paper we describe an information architecture that supports the dynamic composition of Web based lessons based on a database of fine grained components that can be tailored for communities of users. Our goal is to support Web accessible resources of pedagogical material that can be used and reused in a variety of contexts from teacher remediation and lesson preparation to the use of lessons that reflects the diversity of individual learning styles. The Web based lessons are generated on the fly from a database of fine grained components that include explanations, interactive activities, worksheets, images, videos, audio, FAQ's, online questions and challenges. This architecture had been used in the development of learning support systems for two different communities; users of middle school mathematics in one case and users of health informatics learning modules in the other case.