First you need to get familiar with Warcraft 3 models and understand their components, so I suggest you start by trying out some simple model editors and free modeling tools (Retera's Model Studio, Matrix Eater, Mdlvis, War3 Model Editor); that should serve as an introduction to Warcraft 3 modeling.what tools do I need to mod good auras?
I don't think there is a tutorial specifically about auras, but auras are not that much different from any other model. You can find some helpful tutorials here.Is there also a tutorial explaining about modding auras?