Is not very hard, in the begining you just need to create some cameras with diferit view, you have to turn cinematic mode on: Cinematic- Turn cinematic mode On for all players atthe begining of the game.There is a fade efect that turns the image in black and what color you want.You can create dialogs you have to use this:Cinematic-Send transsmison to all players from Unit name Name. Play No sound and display Message...
In cinematic you can issue order units to atack , stand,move, build and some much more.In the end of the cinematic dont forget to TURN CINEMATIC OFF(you cannot play with cinematic mode on)