Thread: problem with an assignement: creating collections class and use them

Well, in my java project , I need to create using netbeans a program similar to the Amazon website, well I post you the link so you can see all of it, it can help you: (c) CJoint.com, 2012

Well I need to make a menu in which the user can register as a member, modify profile etc, browse for books and view their data,etc..
Here is my code from the class Member:

package amazonapplication;
import java.util.Scanner;
/**
 *This class describes a Member
 * @author 
 */
public class Member {
    private String username;
    private String password;
   /**
    * 
    * @param user name as a string
    * @param pass password as a string
    */ 
    public Member(String user, String pass ){ 
        username=user;
       password=pass;
    }
 
    /**
     * Setter of Password
     * @param password the password to set
     */
    public void setPassword(String password){ 
       this.password=password;
    }
    /**
     * Setter of Username
     * @param username the username to set
     */
    public void setUsername(String username){
        this.username=username;
    }
    /**
     * Getter of Username
     * @return the username
     */
    public String getUsername(){ // get method for username
        return username;
    }
    /**
     * Getter of Password
     * @return the password
     */
    public String getPassword(){ // get method for password
        return password;
    }
    /**
     * Method used to change current password
     * @param password current password to change
     * @param newpass  new password to set
     * @return boolean change of password successful or not
     */
    public boolean changePass(String password, String newpass){
        if(this.getPassword().equals(password)){
            this.setPassword(newpass);
                return (true);
        }
        else return (false);
    }
/**
 * Method used to set new password if old one is lost/forgotten
 * @param username member's username
 * @param newpass memeber's new password
 * @return boolean: procedure successful or not 
 */
    public boolean forgotpass(String username, String newpass){
        if(this.username.equals(username)){
            this.setPassword(newpass);
            return (true);
 
        }
        else return (false);
 
    }
     /**
     * Method used to authenticate user
     * @param username name as string
     * @param password password as string
     * @return boolean: authentification successful or not
     */
    public void authenticate  (String username, String password)throws PassException{
        if(this.username.equals(username) && this.password.equals(password))
           System.out.println("Authentification Successful!");
 
        else throw new PassException ();
 
 
    }
    /**
     * Prints member information
     * @return String to print 
     */
    @Override
    public String toString(){
        return "username is:"+this.username+
               "\npassword is:"+this.password;
    }
 
}

And here is my code the class MemberList(not complete yet, i don't know how to do save and load behaviors)

/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */
package amazonapplication;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.LinkedList;
import java.util.List;
import java.util.ListIterator;
/**
 *
 * @author
 */
public class MemberList {
 
    List<Member> members;
    public MemberList(){
        this.members=new LinkedList<>();
    }
    public boolean addmember(Member memb){
        return members.add(memb);
    }
     public boolean removeMember(Member memb) {
        return members.remove(memb);
}
 
}

Well now that I have coded those classes, I should use them for my main
But I don't know how, in my main, I can manage when a user wants to register or do something else from the menu. Does it have a relation with associations ? Its said in my assignement: Finish the implementation of the class Member, a member has an association with OrderList.
Well I am lost

No answer ?