A rather old but still usefull introduction for the starting user is the PRTools4.1 manual. Also the book “Classification, Parameter Estimation and State estimation” has many example scripts using PRTools. There is also an e-book “Pattern Recognition: Introduction and Terminology“, referring to on-line PRTools examples.
The authors are maintaining the website, 37Steps, with more recent information on the toolbox and pattern recognition. It contains a User Guide, a Glossary, a Frequently Asked Questions section, a blog. The toolbox itself contains several example example scripts. If you still have a question, please send a message.