The problem describe below

I have installed magento on my local system, everything is working fine except that the styles are not loading..

I observed that the problem was due to incorrect style sheet url when the request is being sent (found using net in firebug)..

Example:

The request url:

http://yourmagento.com/var/www/yourmagento.com/skin/frontend/default/yourskin/css/layout.css

The request url should be:

http://yourmagento.com/skin/frontend/default/yourskin/css/layout.css 

 

To solve this problem, you can step by step check following\

1, Make sure the ownership of media and var directories to www-data instead of another unix username and giving those folders full permissions.

2, Set Merge CSS Files to “No” in System Configuration -> Advanced -> Developer -> CSS Settings

Source: http://stackoverflow.com/questions/15336647/styles-not-loading-in-magento-due-to-wrong-url-path-how-to-solve-this