Regisitry post type wordpress

I registered a new post type & named it as eassy.

I also added two new users role, one is member_area and another one mentor_area. Now when member_area role users login to dashboard they have to see,edit,delete,publish only there own posts .. and they don't get control over other users posts..

but in case mentor_area users can see all member_area users posts,edit,delete, (full Control).

Is this can be done with WordPress default functions or do i have to use plugins for this? can any one show me a example for this?..

And i also want to know how to show only eassy post type link on left sidbar for member_area & mentor_area dashboard..

add_role ( 'member_area', 'Member Area', array (
        'read' => true 
) );
add_role ( 'mentor_area', 'Mentor Area', array (
        'read' => true 
) );
add_action ( 'init', 'create_my_post_types' );
function create_my_post_types() {
    $capabilities = array (
            'publish_posts' => 'publish_eassy',
            'edit_posts' => 'edit_eassy',
            'edit_others_posts' => 'edit_others_eassy',
            'delete_posts' => 'delete_eassy',
            'delete_others_posts' => 'delete_others_eassy',
            'read_private_posts' => 'read_private_eassy',
            'edit_post' => 'edit_eassy',
            'delete_post' => 'delete_eassy',
            'read_post' => 'read_eassy' 
    );
    register_post_type ( 'eassymamagment', array (
            'labels' => array (
                    'name' => __ ( 'Eassy' ),
                    'singular_name' => __ ( 'eassymamagment' ) 
            ),
            'public' => true,
            'capability_type' => 'eassymamagment',
            'menu_position' => 6,
            'capabilities' => $capabilities,
            'rewrite' => array (
                    'slug' => 'eassymamagment' 
            ) 
    ) );
}

You can create new custom post-type of Eassy:

/*Registery of new post-type:Eassy */
add_action('init', 'create_eassy_taxonomies');
    function create_eassy_taxonomies() {
            register_taxonomy('eassy','eassy',
                              array('hierarchical' => true,
                                    'label' => 'Eassy Category') );
    }

add_action( 'init', 'create_post_type' );
    function create_post_type() {
        register_post_type( 'eassy',
            array(
                'labels' => array(
                    'name' => _x( 'Eassy', 'taxonomy general name' ),
                    'singular_name' => _x( 'Eassy', 'taxonomy singular name' ),
                    'search_items' =>  __( 'Search Eassy' ),
                    'all_items' => __( 'All Eassy' ),
                    'edit_item' => __( 'Edit Eassy' ), 
                    'update_item' => __( 'Update Eassy' ),
                    'add_new_item' => __( 'Add New Eassy' ),
                    'new_item_name' => __( 'New Eassy' ),
                    'menu_name' => __( 'Eassy' ),
                ),
            'public' => true,
            'has_archive' => true,
            'hierarchical' => true,
            'supports' => array( 'title', 'editor', 'thumbnail', 'page-attributes' )
            )
        );
    }

To display this post type :

$args = array( 'post_type' => 'eassy', 'posts_per_page' => 10 );
$loop = new WP_Query( $args );
while ( $loop->have_posts() ) : $loop->the_post();
    the_title();
    echo '<div class="entry-content">';
    the_content();
    echo '</div>';
endwhile;

For user role capabilities editor you can use "USer role editor plugin": http://wordpress.org/extend/plugins/user-role-editor/