Custom menu options in admin

hello,

I am new in theme customization, but I am trying to develop my own theme.

At the moment I have no problems with the public side customization, but I don’t know hoy to modify and add menus to the admin.

What I am trying to do is to create a menu for the portfolio section, where the admin can upload tow pictures for the thumb’s rollover and a url for a vimeo video.

Can anyone point me to a tutorial or give me somo advice to achieve that.

Thanks a lot!