Course registration automation

Hey
I have a WP site using WP Members plugin.
Customers purchase my eBooks, then create a user account via the membership plugin.
I've been manually approving new students. I need to automate that process.
The steps are as follows:
-They download the eBooks via GetDPD.com (which I highly recommend)
-They receive an email (via DPD) with a link to go create an account
-I get an email (via the plugin) that "a new student has registered"
-I verify they bought and approve them in the plugin for video access, hosted on my site
-They get an email with their password

So, how do I automate purchase verification and approval?

Thanks for your time.