I've done a few custom themes for WordPress but I'm looking to get further into specialized themes and plugins. Please point me to specific pages in the Codex if that is easier than answering the questions below. Thanks.
As for plugins, my main question is how to provide a data field in the WP control panel, for either a theme or a plugin, that a user can enter data into, likely some html embed/object code. Many of the plugins provide this for settings and such but I'm confused how one stores this into the database.
Also, there is mention that the footer can be used to "hook" includes into a web page. I'm not sure how these "hooks" work.
Any direction or help would be much appreciated.