Shadow priest 101: How to melt faces effectively

Advanced shadow priest studies.
http://elitistjerks.com/f31/t16977-shadow_priest_101_how_melt_faces_effectively/

Contents
1. What is a Shadow Priest? (And Key Terms)
2. What are the key talents for a Shadow Priest?
3. What are the important stats for a Shadow Priest?
4. What gems/enchants are good for a Shadow Priest?
5. What sort of gear does a Shadow Priest wear?
6. What is some basic information on Shadow Priest spells?
7. What is a spell priority system, and how does it apply to Shadow Priests?
8. FAQ