There are plenty of mods available already.

Two of the best sites for these are AOC Curse Addons (Other Addons) and Conan Mods

Some of the other tools worthy of mention are:

• Age of Conan Quick Start - lets you skip the intro videos, clears your shader caches and much more
• AOC Custom UI Patcher - Patch your custom UI changes to have the latest version number so they work after a patch
• Wayfarer - Keep your map notes updated from a central database to make resource harvesting a breeze
• Ventrillo/Teamspeak - Voice chat is just so much easier, particularly when grouping (be sure to check out the alternative overlay)
• AOC-Tools/DPS - Analyze your combat logs.  Currently somewhat buggy and undergoing a rewrite.  I'm actually in contact with the author of this and may contribute some code myself in the coming weeks.