For "to speak or read something aloud for someone to write down":
* Read out
* Enunciate
* Pronounce
* Recite
* Scribble (informal, implies quick writing)
For "to give orders or instructions with authority":
* Command
* Order
* Prescribe
* Stipulate
* Mandate
* Impose
For "to influence or determine (something) decisively":
* Control
* Govern
* Shape
* Determine
* Influence
The best alternative will depend on the specific context in which you are using "dictate".