Confused on structs and arrays

I'm supposed to write a program that is able to save a list of items such as books, CDs, or DVDs. The items that are saved must have attributes associated with them. For example a book has a title, author, publisher, and ISBN.
I'm supposed to create a program that is able to save the database of items to a file on the hard drive and also retrieve it from the hard drive.

The user should be able to

1. Enter items
2. Display a list of the items
3. Save the list to disk
4. Read the list from disk
5. Sort the list
6. Exit the program

I know I should use arrays and structs but can anyone give me a head start?

Start with number 1 first.

Can you be more specific what you need help with? e.g. do you know how to get input from user? how to create a structure/array?

Have you tried anything? then post the code you have.

So far I only have

<iostream>
<fstream>
#include
using namespace std;

int main()
{


fstream file;
file.open("file.dat", ios::in);

}

So pretty much I have nothing. I don't know what my first step should be. How do I create a .dat file?