This free online linear algebra course teaches introductory concepts in vectors and matrix algebra. The course will consist of around 60 tutorials which cover the material of a typical first year linear algebra course at the university level. Tutorials 1-44 are complete and the remaining tutorials are in development.
In order to gain a comprehensive understanding of the subject, you should start at the top and work your way down the list. That way you will start learning the most basic concepts first and build off of those as you progress through the course.