Over at the EMS 12-Lead blog there is a series of posts on this topic. The first post, available here, contains the links to the other five. These are not like the discussions you'll find in formal review articles or textbooks. They deal with real world situations encountered in the emergency setting. The author deemphasizes morphologic criteria and reminds readers of the adage “a wide complex tachycardia is VT until proven otherwise.” You'll make fewer mistakes if you start there. When you're under the gun in the emergency setting you don't want to waste too much precious time trying to make a fancy morphologic diagnosis. Later on when you have time to scratch your head, or in stable patients, you can do a detailed morphologic analysis. The most widely used criteria nowadays are the Brugada criteria. Those criteria are easily misunderstood. The original Brugada paper explains the nuances and limitations of the method. It also reviews and references the older more traditional morphologic criteria. The latter have serious limitations but may warrant consideration if the Brugada criteria fail to yield a definitive diagnosis.
Finally, it is increasingly being recognized that extracardiac causes, particularly hyperkalemia and drug overdose, can lead to some bizarre wide complex tachycardias. Although these do not fulfill criteria for SVT with aberrancy many are not VT.