Relate table to node - How does this work?

I'm having some difficulty understanding the functionality of relating a table to a node. I read through http://drupal.org/node/898562 and figured the same would apply to D7, but when I get to "Add Node Title field" I'm unable to move forward as this isn't a field that is available.

I have a considerable amount of data in a table in the database that will be updated on a fairly regular basis. I'd like to be able to create a content type that uses this data, but I cannot seem to get the two linked together. I have not successfully found much documentation on this feature at all. Is there somewhere I can find the information I need? Perhaps a helper module that someone can point me to?