Helm

Official docs outline

Using Helm
Charts, releases, repositories, and the install, upgrade, rollback, and uninstall lifecycle.
Chart Structure
Chart.yaml, directory layout, versioning, templates, values.yaml, and chart dependencies.
Chart Template Guide
Go templates for Kubernetes manifests, built-in objects, and rendering.
Values Files
values.yaml defaults, overriding with -f and --set, and value precedence.
Template Functions and Pipelines
Sprig functions, pipelines, default, quote, toYaml, and indent.
Flow Control
if/else, with, range, variables, and whitespace control in templates.
Named Templates and Helpers
_helpers.tpl, define and include, and reusable template partials.
Subcharts and Globals
Dependencies, parent-child value passing, and global values.
Chart Hooks
pre-install, post-upgrade and other lifecycle hooks, hook weights, and delete policies.
Chart Tests
helm test and test pods for validating a release.
Repositories and OCI Registries
Chart repositories, index.yaml, pushing and pulling charts over OCI registries.
Provenance and Signing
Chart signing, verification with GPG, and supply-chain integrity.
Library Charts
Shared template-only charts used as dependencies.
Debugging Templates
helm template, lint, --dry-run, and --debug to diagnose rendering errors.
Chart Best Practices
Conventions for values, templates, labels, dependencies, and RBAC.

Each section links to the official page. Titles and summaries by Extra Credit; the docs belong to their authors.