Creating a plugin that uploads data to the DB

Hi all,

I am trying to build a plugin that inserts data into a table (a custom table, not a WP table).

I have figured out how to create a basic plugin with a form, but am unsure about how to submit and process the data from the form. Can anybody give me a hint or point me in the direction of a good tutorial?

If I have:
<form method=”post” action=”insertdata.php”>
I just get a 404 error.

Likewise if anyone could tell me how to have multiple pages appear for the plugin in the admin panel that would be great as well!

Thanks heaps!