There is a lot of PHD2 information and a lot of tutorials out there on the web. Some are good and others are junk, but how to tell the difference?
I choose to rely on the recognized community experts. Below are links to the only PHD2 resources that I use. Period.
Optimizing Guiding with PHD2, Bruce Waddington
Demystifying the PHD2 Guiding Assistant, Bruce Waddington
Or anything by the primary PHD2 developers, Bruce Waddington or Andy Galasso. Other video tutorials by them may be added later.
How to Create a Baseline for PHD2 Guiding Results
Analyzing PHD2 Guiding Logs, A Basic Tutorial
PHD2 Troubleshooting and Analysis, PHD2 Manual