I'm going to get right into the nitty gritty on making you're Drupal installation more SEO Friendly with the intent of increasing traffic and page rank!
1. Pathauto
This module is going to automatically generate a SEO Friendly alias for your content that you are creating. This module is dependant on Token so you will need to make sure you have that module loaded first before enabling Pathauto
Download PathAuto || Download Token
Make sure to read the documentation for Pathauto if you already have content populated on your site