Drupal and URL aliases
The basic form of URLs on Drupal are as follows:
http://www.villa-la-herradura.com/?q=node/157
These are known as 'dirty' or 'unclean' URLs and are not good practice for search engine optimisation.
So the first transformation is to go about getting 'clean' URLs. This is easily obtained by selecting 'Clean URLs' under Site Configuration. And then selecting 'Enabled' for clean URLs. Note, your server will need to support this feature.