adding data to an existing content type programmatically
Matt,

To create a node programmatically, 


You firstly need to create a content type for same. This will make sure that Drupal architecture is followed to create a node.
Now you need to create a node from UI, and in hook_node_presave, make sure you print the node object - dprint_r($node); die; and see what is the Object architecture like.
Now you need too create the same object before saving it.
To, create the object, create $node = new stdClass();, define the node type $node-&gt;type = 'YOUR CONTENT TYPE NAME' and do a node_object_prepare($node), this will make sure that all the basic settings are added to the node object.
Post this, make sure you create the object, same as it was in node presave stage.
Just before calling node_save, call node_submit, which will prepare the node for submission.


Hope this helps !!!