I just wanted to mention a few things that will be helpful going forward:
Documentation
The best place to get documentation is Valadoc.org, even if you aren't using Vala. Those poor souls using C may want to use the official docs instead. Note that Valadoc.org will sometimes have C-specific information about Clutter, which can be ignored (this is because Valadoc.org's contents are automatically generated from doc comments in Clutter's C source code, and these comments sometimes document C-specific semantics of the library or give examples in C).
Here are the main things we used in previous chapters, so you can investigate more deeply if you want. Most of these topics will be given further coverage in later chapters anyway.
Editors
You can get along perfectly fine using your favorite text editor (I recommend Geany) and a terminal to build/run. For complex projects, MonoDevelop is a solid IDE with Vala support (but its Vala support seems to have broken in the latest version).