i wish to give authors who register to my website a custom "add new publish" page. I am talking about once they try to create a new publish they'll click on the posts->add new and they'll be given specific fields to fill. Like filling a custom form with textboxes and dropdown lists.

If anybody can provide me ideas..

Thanks

Possibly one of these simple plug ins is useful for you... Or at best might provide you with a nice beginning for which you are searching for. The concept behind these is you can simply edit content around the "front-end" of the site (without engaging in the WordPress back finish).

These plug ins might integrate with WordPress's built-in registration (author) authentication. Otherwise, I am sure you can wrap the code within an author drenched under control.

This wordpress plugin looks great for giving authors a chance to have an "About Me" section within the footer of the article:

Discover acquainted with WordPress development and are curious about learning, I'd recommend obtaining the book Digging Into WordPress (and associated blog). Otherwise I am sure you are able to employ a developer to implement the thing you need.