Hello, I'm new to the fields/CCK api, and having a bit of trouble getting Drupal 7 to see my field.

I found the field_example module in the examples.module, and found the corresponding presentation on Acquia TV (though the text was too low res to read). 

I'm able to copy the RGB Color field example, enable it, and Drupal 7 sees and uses it without a hitch. I tried replacing instances field_example with mymodule but then Drupal stops seeing the field even after a drush dis mymodule && drush en mymodule. 

In the presentation the speaker said that all fields had a few minimum hooks, but I couldn't quite make it out on the screen. I tried to make a minimal field using just hook_field_info, hook_field_is_empty, hook_field_schema, and hook_field_validate, but I seem to still be doing something wrong. 

I can post my code to the mailing list if desired, but I think what would really help me is if there is a minimal example of using hook_field_info and friends somewhere on the internet I can read through? I'm really not sure  where I'm going wrong in my code (no php errors or watchdog warnings, field just doesn't become available.) A smaller more digestible example would probably help me greatly. If not, can anyone point me to what hooks are the bare minimum that need to be implemented?

As an alternative to field_info I started using hook_node_presave() to mish-mash values, but I get an impression that's not the best way to make a custom field. 


Thanks a bunch,