I want to create a user form that will be filled by an enduser. I'd like to store the forms data in the database.
If you just want to add a simple contact then look at Contact Form by Pixel & Tonic.
For anything more complex then I'd suggest looking at the Guest Entries plugin also made by Pixel & Tonic. This enables you to use front-end forms to post to the database.
You may also want to look at the docs for creating User registration forms on the front-end.