development structure of site

Hi,

I'm looking for some advice. I'm fairly new to drupal but I want to learn how to build my site without hiring someone - maybe a little work will need to be done but I want to see how far I can get on my own.

I want a site where customers can log a 'job' by filling in a form. I want a field to automatically generate a 5 digit 'job' number when the form is submitted. Users could see what jobs they've submitted and have the option of 'closing' a job.

I then want a selection of 'workers' who have permission to view a list of open jobs including job number and selected other fields the user filled in.

Also for the workers to have profiles and maybe a feedback system.

Can anyone be kind enough to suggest a selection of modules I would need for this and a basic stratagy I would need to follow to get this set running.

Thanks in advance.