Well, my method may not be the best, but it's all I know.
Firstly, create two events. Make them the characters you want to talk, and name them (optional, but it'll help in the long run). Now, create another separate event that you want to step on to get the cutscene rolling. Make it touched by hero, and below hero. Make it pan screen up however many tiles you need, and you can now add other desired effects (i.e. shake screen, music, fade in, etc.).
Here, you can add a face graphic for the first character to talk, and change the additional extras on it (such as placement of message, transparency), or just go right onto the message.
Now, if you want one of the two characters to move, here is where the naming of the events comes in handy. Select move event, and choose one of the two characters by their name, and then you can do whatever. Make them move, spin around, face different directions, and so on.
When you finish making the characters do whatever, pan screen back down. If you want the characters to remain, skip this following step.
Select change graphic for one of the characters, and change it to a blank tile, and move the event somewhere you can't access.
There are other easier methods, but this is the one I know. Fiddle around with it, experiment, and have fun!