This is where you will store the documents that you send to companies that you apply with: position descriptions, copies of completed applications, cover letters, resumes - anything you sent.
The best way to organize your documents is to use “a to z” index dividers so you can keep your materials in alphabetical order by the company name.
If the employer calls in response to your application, you want to make sure that you're on the same page. You need these materials in hardcopy because you will probably be sending slightly different versions of your documents for each job that you apply for. If an potential employer is asking you questions about your resume or application, you want to make certain you know what you said ... at the very least, you want to make certain that you know exactly what you put down on your resume for your "career objective."
And if the employer calls to screen you by phone, or if you need to prepare for an interview, you really want to be able to quickly find the job description. If an employer calls, nothing is less impressive than a candidate who cannot remember which job they applied for.
"Could you tell me which job we are talking about?" is a non-starter ...
Your Career Binder: the ideas and inspiration section
Staying Organized with a Success Timeline
Staying Organized with a Daily To Do List and Calendar
Your Career Binder: the job search contact notes section
Here: Your Career Binder: the job applications and resumes sent section