Assigning Content

I have done this both ways. I have students that move at their own pace and grade levels, so assigning and keeping up with who is where was difficult for me. 

I now prefer to have them move from topic to topic on their own showing me every other day where they are. We have discussions about their progress and pacing. 

It is probably a little more work this way, but with the digital curriculum doing the teaching I can focus on the relationship aspect of teaching. I also use the one-on-one discussion time as a formative assessment. If they can put their learning into words, they are truly "getting it". 

Hope this helps. :-)

I know this is an older post, and I hope you have found a workable solution. I tried using Khan Academy in the way you described, but I found it difficult to track student progress. 

I created classes, and populated them through our school's Google account. Even if you do not have one Google account for your students, it is very easy to create and populate classes. Once I have classes set up, I assign them content. You can assign as much as you would like, and have a due date of your choice. I assign about a weeks worth of work, and download the results to an Excel file. This approach also gives me information by class, as well as specifics about each assignment, such as when it was completed, their best score, and the number of attempts that were made. 

Even if you do not assign specific content, I would suggest creating classes in Khan Academy. There is quite a bit of information available.