The Basics

[Zalasta]

DoT's, DoT's and MOAR DoT's

http://ffxiv.zam.com/wiki/Thaumaturge_101_%28FFXIV%29

This wiki guide is probably what you're after

It needs some updating for the new patch, but most of it is still useful.

some con spells like fire,blizzard, etc

This is no longer true, I believe Banish and Scourge got a damage boost is the recent patch. Although those CON spells are nice to have as well.