Over the last three years, I've been working with the San Diego County Office of Education with their online science courses for teachers in special situations (VPSS). As part of that project, I have used their Learning Management System (LMS) called Haiku, and I have nothing but good things to say about it. Haiku is easy to use both for teachers and for students, it has a lot of capabilities, and I think it just might make your life easier if you're trying to teach a blended or flipped class to any degree. Teachers can sign up for free (limit of 5 classes, 375 kids, 2 GB file storage). There are higher capacity plans available for a small cost (starting at $5 per month).
I've used Blackboard, and Moodle, and Sakai, and they're fine, but in my experience, Haiku is simpler and better than all of them. Give it a try at www.haikulearning.com.
