The usual dosage would be in the range of 250mg-750mg a week. This level is quite sufficient, and should provide the user a rapid gain of strength and body weight. Above this level estrogenic side effects will no doubt become much more pronounced, possibly outweighing any new muscle gained.
Those looking for greater bulk would be better served by adding an oral like Anadrol or Dianabol, combinations which prove to work great. If one wishes to use a testosterone yet retain a level of quality and definition to the physique, an injectable anabolic like DecaDurabolin or Equipoise may prove to be a better choice. Here we can use a lower dosage of enanthate, so as to gain an acceptable amount of muscle but keep the buildup of estrogen to a minimum.
With the proper administration of ancillary drugs, Nolva/Clomid , during post cycle recovery, much of the new muscle mass can be retained for a long time after the cycle has been stopped.