Getting shipping and billing addresses from a guest-checkout order

Let's say that you have the order id 10000015: So

$orderId = '10000015';
$order = Mage::getModel('sales/order')->loadByIncrementId($orderId);
$billingAddress = $order->getBillingAddress();
$shippingAddress = $order->getShippingAddress();

Get shipping details by order id

$order_id = 2314; //use your own order id 

$order = Mage::getModel("sales/order")->load($order_id); //load order by order id 

$shipping_address = $order->getShippingAddress();

 echo $shipping_address->getTelephone(); 

echo $shipping_address->getPostcode(); //use print_r($shipping_address->getData()); to get all the available elements of the object