Laravel Eloquent Many to Many relationship using a pivot table

I'm working on creating my own Project Manager, I currently have a projects, users and a project_users table. I am trying to create the relationships in the models to associate one project to many users, but I have never created a many to many relationship. I looked at the documentation and tried various examples but none worked for me.

Here is my ProjectController:

public function single( $id ) {

$project = Project::with('client','projecttypes','storys', 'sprints', 'projectusers')->find( $id )->toArray();

return View::make('projects.single', array( 'project' => $project ) );

}

This is simply grabbing a single project and all of the related models and returning them to the view.

My Project model:

class Project extends Eloquent {

    /**
     * The database table used by the model.
     *
     * @var string
     */
    protected $table = 'projects';

    protected $fillable = array( 'client_id', 'title', 'description', 'type_id', 'status', 'hours_estimated', 'hours_actual', 'date_estimated', 'date_due', 'date_completed', 'created_at', 'updated_at' );

    public function projectusers() {
        return $this -> hasMany( 'User', 'id', 'user_id' );
    }

}

My users model:

use Illuminate\Auth\UserTrait;
use Illuminate\Auth\UserInterface;
use Illuminate\Auth\Reminders\RemindableTrait;
use Illuminate\Auth\Reminders\RemindableInterface;

class User extends Eloquent implements UserInterface, RemindableInterface {

    use UserTrait, RemindableTrait;

    /**
     * The database table used by the model.
     *
     * @var string
     */
    protected $table = 'users';

    /**
     * The attributes excluded from the model's JSON form.
     *
     * @var array
     */
    protected $hidden = array( 'password', 'remember_token' );

    protected $fillable = array( 'client_id', 'title', 'first_name', 'last_name', 'address', 'city', 'state', 'zip', 'email', 'password', 'status', 'created_at', 'updated_at', 'remember_token', '_token' );

    public function project() {
        return $this -> belongsToMany('Project');
    }

}

and finally my ProjectUsers model:

class ProjectUsers extends Eloquent {

    /**
     * The database table used by the model.
     *
     * @var string
     */
    protected $table = 'project_users';

    protected $fillable = array( 'project_id', 'assigner_id', 'user_id', 'notifications', 'created_at', 'updated_at' );

    public function project() {
        $this -> belongsTo('Project');
    }

}

All fields in the database are listed in the models $fillable with the exception of the primary id id.

I just need to figure out how to get all users assigned to a specific project utilizing the pivot table, any help would be greatly appreciated!

Thanks