You can subscribe to do online email courses.  These courses are conducted by sending you an email per day with the relevant material.  They are usually not longer than one week, which means that you will receive an email with the relevant matrial every day for seven days.

These courses are free of charge. 

Click here to see the subjects for which Van Thinking makes available email courses at the moment (you will be taken to www.main.vanthinking.com when you click on theis link).