These tutorials cover a range of material that, depending on where you go to school, might show up in either mechanics of materials 2 or structural analysis courses. Here at engineer4free, I've decided to go ahead and call it "structural analysis." A solid understanding of mechanics of materials is necessary to understand the topics presented here.
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.