I'm helping the team of teachers I work with to build their own courses in Moodle and gathering screencast tutorials as I go...
Here are some tutorials for teachers at the 'starter' end of things, covering some basics concerning the building of downloadable work files (in a variety of different formats) and creating an assignment upload option.
In essence, this allows you to feature content or work files (for reading, viewing or writing) which the learners download and complete. They can then upload it for the teacher to view and grade via the upload option.
I've generally found that this is a good starting layer for teachers who want to allocate and collect task work on Moodle. There are other (more advanced) options, of course, but these skills are pretty easy to master and facilitate teachers getting a course happening without too much of a steep learning curve or big investment of their time (and hair pulling).
Another (major) advantage with the file download/assignment upload approach is that learners can save work files to their computer and not necessarily need an Internet connection or continuous access to Moodle in order to do their work.
Trust me... after a week that included major Internet access and operating system problems, I can assure you that this can be REALLY handy!