Here's what I would like to achieve:
Let's say I purchased the subscription at 9:30am, I would receive a welcome email instantly followed by a separate email containing a PDF with part 1 of the 12 week course (the PDF may, or may not, be password protected). Parts 2 through 12 would then be emailed to me at the same time each week until the course was complete (after 12 weeks). I would also like to send a follow up email after 1 further week.
Let me know if that doesn't make any sense.