I'm one of the regular writers at WPMU.org. I've started a series of tutorials for WPMU DEV plugins and thought that it might be a good idea if I let you guys know about them (since you're all using the plugins!)
To start with I've written "Create a Simple Tutorial Site with the WPMU DEV Membership Plugin"
You can check it out here: https://premium.wpmudev.org/blog/create-a-simple-tutorial-site-with-the-wpmu-dev-membership-plugin/
I'll be doing more over the next few months. If there are any specific tutorials (within reason!) that you'd like me to do let me know and I'll see if I can put them together. I'll do some more on Membership over the next week or two.