Starting from the beginning
Let's go to work with the QSR only:
The LN [Lead Narrator] begins the turn by giving a narrative of the
current situation and advancing the plot, as described
under Event Briefs (see p. 11). The LN also makes any
actions or die rolls for enemies the characters may
encounter. Though the LN begins the turn, he is the last
to act with his character.
This implies something the LN needs: A (basic?) Event Brief, so you might staple together some scenes you want to see run for the day your brief gets played. Like a description of some areas, plot hooks and people present... how an event brief looks sadly is pulled to the end, so we look at them a tiny bit later.
Then, you need to "roll for enemies". Enemies means, you need to prepare a few dossiers for goon characters and maybe a villain or two for the whole group to use - a pool of these would be quite a good idea.
Now the rules tell us a turn is the smallest part and that we need to frame them in scenes. Scenes need a starting and an ending point and that multiple scenes make the event brief. During a scene, the LN doesn't change, so it you can plan out objectives/steps you want to run in your scene quite reliable. But how scenes are planned is in the Event Briefs section.
You can't prepare for this beforehand, but as your turn as LN ends, subsum the whole scene for the next LN and give him a 'well set stage'. The next LN will be grateful to have a little help in connecting his scene with yours.
Now the the QSR failed to mention in the start, but it might be a good idea to bring some kind of tokens to denote Plot Points. I strongly suggest to use something like coins or a marker on a track to show clearly to everybody "the LN has 12 PP, Cryofrost has 2 and Megaboy has 1." This might reduce the discussions at the table.
Now, we had mentioned the Event Brief before, the QSR detail them at page 11 following, but start of with the example on page 9.
Because, while our Event brief will start at some point, the heroes/villains of the group will need some background. Make some notes that lead to each of them being as they are. Like the "power origin" or "year 0 issiue".
Then follow the example briefs, that follow up on each other - as each evening should (to my understanding) run only one brief, it might be a good idea that everybody prepares one brief with some scenes that he things should be in it, and then somehow choose one of them - maybe rolling a die. The other briefs are stored for later use. For next week, you might need to write another brief to conclude the arc started the last week, but after the arc is finished, those stored briefs should be taken into consideration.
Make sure to have a good set of notes to start of those scenes in the event brief - well enough for everyone to grasp the idea of them and who is present - but make them flexible enough to work in how your previous LN ended his scene. As the QSR implies, every LN (and thus every player) gets the notes that the maker of the event brief made, so make sure they are readable by everyone and clearly pointing towards the specific ends.
- Bring something to count Power Points!
- Bring an event brief with notes about the scenes that should be run in it. As you won't be running all the scenes, make the descs
- bring a stack of villains with their "year 0"/"origin story" for the pool
- bring a few NPCs for the pool, best with short characteristics
- bring some goons on a sheet for the pool
- bring your own character (sheet) with its own year 0
- bring a set of scene-starters/notes to run generic scenes if everything else fails
Maybe, just bring the printed QSR and try out the system with the premade plot together. It seems to be well enough made to get the gist of the system and be over in 2 to 3 sessions.