[development] Forms API newbie guide?

I'm just starting out trying to create my own module, and am having problems understanding some concepts. I'm finding the online docs/api to be lacking in some areas. So I was hoping someone might know of a good resource to building a module that will include creating a form and inserting/updating form data into a database table. I'm looking at Drupal 4.7, and have partial success with the Form API. I'm able to insert data, but updating is failing miserably. I'm sure my approach is not correct, but don't see much in the docs to help me out. (I don't *think* it's a question of how to use code, but more of how to use the framework - the APIs address the code part.) Thanks for any tips. Shawn