- [How VSCode's sourcecode is organized](https://github.com/microsoft/vscode/wiki/Source-Code-Organization) - this explains where the entry point files are, what `browser/` and `common/` mean, etc. This is the most important read on this whole list! We recommend reading the whole thing.
- [Built-in VSCode Styles](https://code.visualstudio.com/api/references/theme-color) - CSS variables that are built into VSCode. Use `var(--vscode-{theme but replacing . with -})`. You can also see the [Webview Theming Guide](https://code.visualstudio.com/api/extension-guides/webview#theming-webview-content).
- ["Contributes" Guide](https://code.visualstudio.com/api/references/contribution-points) - the `"contributes"` part of `package.json` is how an extension mounts.
- [The Full VSCode Extension API](https://code.visualstudio.com/api/references/vscode-api) - look on the right side for organization. The [bottom](https://code.visualstudio.com/api/references/vscode-api#api-patterns) of the page is easy to miss but is useful - cancellation tokens, events, disposables.