Custom post types are a great way to give a real customized feel to your WordPress site. Theme developers can use custom post types when writing custom themes for their WordPress clients. Essentially, a custom post type is essentially the same thing as a post or a page, but your own way of organizing information. For example, on our site, we have a custom post type called “Portfolio” where we can organize all of our portfolio entries separate from our blog entries or pages. Using custom post types is a great way to utilize WordPress as more of a CMS (content management system) rather than a blogging tool.
Here is a link to a great online WordPress custom post type generator: http://generatewp.com/post-type/. They also have a lot of other great wordpress code snippet generators as well. Generators are a great way to save development time and troubleshooting headaches. Of course, it is always good to understand the logic behind the code the generator creates. Here is the link to the WP documentation on post types (just in case): http://codex.wordpress.org/Post_Types.
Here are some great resources for more reading on how to use custom post types in your WordPress site: