Learning is an interactive process that involves the learners, teachers and the contents. With the massive growth in WWW technologies, learning has become a ubiquitous process where there are no restrictions on the time and place of learning for the learners. The support for online learning has paved the way for easy access to the educational resources and also given the learners the comfort of learning from their home. This paper focuses on the related works in the field of e-learning and highlights the importance of the contributions being made towards addressing the issues with the learning contents and the effectiveness of content delivery for the learners. The contents of this paper are organized under the topics viz. Introduction, learning contents, learning object repositories, learning object metadata, learner profiles, generating learning experiences and adaptive content recommendation.