How can I publish a channel entry without using the publish form? I'm trying to do this via an extension hook.

In short, here’s what I’m trying to do: When a new user is created, a channel entry is automatically added with the same title as the name of the new user.

But what’s the best way to add a channel entry outside the publish form? Is there a way I can easily determine the MySQL INSERT INTO statement that is used to create a new entry? All I really need to add is the title and the other required entry fields, but I know EE stores this data in a couple different tables and don’t want to overlook one if I end up creating this query manually.

Thanks.