PHP and MySQL database, accounts, and form

General information for the website: The website is an online form to collect user information
Description of requirements/features: We need someone skilled in php and MySQL for the following...

We already have a front-end (html&css only) created, with a multipart form (approximately 23 fields).

We need to add php/mysql for:-

1. login/logout/reset password.
2. changes between multipart form - the website has a looped video background, so the multipart form should change 'in page' (possibly ajax?) rather than calling a new page.
3. verify form fields.
4. submit form (after a 'user agreement' is displayed).

In addition, some users (admin user) will display a table once logged in. The table needs to be expandable to display extra fields for records, and be editable. You are free to use whatever table scripts you are familiar with for this, as long as the css/style keeps with the look of the site.

Finally, the database created needs to be well formed and commented, so it is easier for someone inspecting it to understand.

Screenshots are attached below.
Extra notes: