You may find the following sources of information useful.
The latest versions of all the Graphcore software documentation including user guides and technical notes
The Graphcore GitHub examples repository has application examples
The Graphcore GitHub tutorials repository has examples of features and simple applications, and tutorials
There are Graphcore videos with explanations and demos of Graphcore software
The source code for TensorFlow for the IPU on GitHub
The TensorFlow model repository on GitHub an excellent reference for various model implementations
The book Hands-on Machine Learning with Scikit-Learn and TensorFlow a very useful practical guide to developing and training network models using TensorFlow