Here is a sample video from a chess master. He starts with beginner fundamentals and takes you through advanced topics.
Chess tactics is a very important skill to develop as the middle game can make or break you.
Don't have a clue how to play chess? Know how to move pieces, but don't know about en passant or castling rules? Already a good player? There's a lesson for you. :)
Research has shown that students who played chess had progressed significantly in the following areas: self-satisfaction, self-confidence, healthy, joyful, identifying problems, thinking of alternatives, assessing alternatives, confident performance, review, satisfaction with the teacher and school, enjoying studying, good behavior, peaceful attitudes, respecting rules, and broad sociability.
Here is a video showing the chess tournament I co-hosted at my old school. I can't wait to do a tournament here, at our school!