Understanding the Drupal lingo:

Drupal glossary

Adding and managing content:

Content management in Drupal

Taxonomy:

Taxonomy: A way to organize content
Drupal Taxonomy, Drupal Nodes And Other Terms - What Do They Mean?
Drupal Taxonomy Tutorial

Tag cloud:

Using tags and tagclouds to describe your content in Drupal

Photo gallery:

How to make a photo gallery with thumbnails in Drupal

SEO:

Basic Drupal SEO: On-site Optimization
Creating an SEO Strategy (for a Drupal website)

Showcase (websites in Drupal):

Drupal Projects Showcase
Drupal websites
CMS Showcase: 31 Remarkable Drupal Powered Websites

And last but not least, some of my favourite drupal-powered websites

About Seafood
Asia Travel
Francesca Battistelli
Naturally Splendid
Perreo Radio

[tags]tutorials, cms, drupal, content management system[/tags]