The site is set up in two ways to accommodate teachers who are teaching in different locations. Firstly, we have them organized into grades for B.C. teachers (because we are a B.C. company). So if you teach grade 6, I would suggest using the grade 6 course and you could simply follow it as it is.
The videos are in order for each concept and the concepts are sequenced in the order I feel is most logical. You may wish to alter the order of the concepts (like teaching algebra before decimals). There are many different sequences that would work well, this is just one. The important thing is to link the concepts to the big ideas and to each other regardless of what order you decide to teach them.
If you are NOT a B.C. teacher then you may prefer to use the courses that are set up for each concept and decide where you need to start based on your curriculum and your students.