WordPress is not merely a blogging tool. Creating custom posts and taxonomies gives you a robust content management system.
The following are excellent readings and plugins about custom posts and taxonomies.
How and When to Use Taxonomy
When to (not) use a Custom Taxonomy on Ottopress. This is the best online definition of taxonomies that I have found.
Plug-ins
Types – Custom Fields and Custom Post Types Management. This is an excellent, stable plugin that is compatible with WPML and Genesis Framework.
Note: In creating and managing custom posts and taxonomies you have the option of adding these in your functions.php file or by using a plug-in. My vote is the plug-in: It saves you time, it allows for greater ease in updating and changing themes, and organizes your custom posts and taxonomies. There are numerous options out there, too.