Learning to create custom content types programmatically in Drupal is like jumping without a parachute.  The documentation in the core API is very limited.  I’ve create a short list of websites that have generated useful helpers and tutorials. I hope they help you, please leave a comment if you have any other useful links.

• Working programmatically with fields in Drupal 7
• Drupal 7 – A Simple Content Type
• A Simple Content Type: Using the Select Widget
• A Simple Content Type: Adding Checkboxes and Radio Buttons

Here is the link to the standard drupal core file that installs article content type

http://api.drupal.org/api/drupal/profiles!standard!standard.install/7

I would just like to add the Andy Pangus (http://www.andypangus.com) has some really interesting articles and well worth a few minutes of anyones time.