This post help you to get url, directory path, to get module URL. This is very basic post, that will help to magento designers or beginners.
Get Url in phtml files
Get Base Url : http://localhost/magento/
echo Mage::getBaseUrl();
Get Skin Url : http://localhost/magento/skin/
echo Mage::getBaseUrl(Mage_Core_Model_Store::URL_TYPE_SKIN);
Unsecure Skin Url : http://localhost/magento/skin/frontend/base/default/images/imagename.jpg
echo $this->getSkinUrl('images/imagename.jpg');
Secure Skin Url : http://localhost/magento/skin/frontend/base/default/images/imagename.gif
echo $this->getSkinUrl('images/imagename.gif', array('_secure'=>true));
Get Media Url : http://localhost/magento/media/
echo Mage::getBaseUrl(Mage_Core_Model_Store::URL_TYPE_MEDIA);
Get Js Url : http://localhost/magento/js/
echo Mage::getBaseUrl(Mage_Core_Model_Store::URL_TYPE_JS);
Get Store Url : http://localhost/magento/
echo Mage::getBaseUrl(Mage_Core_Model_Store::URL_TYPE_WEB);
Get Current Url : http://localhost/magento/
echo Mage::helper('core/url')->getCurrentUrl();
Get Url in cms pages or static blocks
Get Base Url : http://localhost/magento/
{{store url=""}}
Get Skin Url : http://localhost/magento/skin/frontend/base/default/images/imagename.jpg
{{skin url='images/imagename.jpg'}}
Get Media Url : http://localhost/magento/media/imagename.jpg
{{media url='imagename.jpg'}}
Get Store Url : http://localhost/magento/mypage.html
{{store url='mypage.html'}}