From the Book - 2nd edition.
Part 1: Getting started with GitHub.com. Understanding the Git in GitHub
Setting up your collaborative coding environment
Part 2: Starting your first solo project. Introducing GitHub repositories
Setting up a GitHub website repo
Creating a website with GitHub pages
Part 3: Contributing to your first project. Forking GitHub repositories
Writing and committing code
Working with pull requests
Part 4: Manage and contribute to large projects. Exploring and contributing to OSS
Inner-source your code on GitHub
Part 5: Make GitHub work for you. Collaborating outside of GitHub
GitHub workflow integrations
Part 6: The GitHub ecosystem. Exploring the GitHub marketplace
Part 7: The parts of tens. Ten ways to level up on GitHub
Ten ways to improve your development workflow
Ten tips for being an effective community member