Help me prep my game!

[beejazz]

It's my first time DMing in ages, so I want to start with something I'm comfortable with. Mainly, a dungeon crawl full of stuff I can lift straight out of the monster manual. Maybe some homebrewed traps, because those can be fun. I've got next to no ideas for the dungeon crawl itself (I want to incorporate a bunch of dead people, an item that will drag the PCs into the plot later, and an underground body of water... preferably occupied by appropriate water-based nasties) and, for once, have a bunch of ideas for the greater setting, and what to do after the dungeon (though, again, no idea how to link them).

I'll give you kind of a top-down look at the big plot.

1)There's a big bad. He's a lich. He's trying to go from being a lich to being a god, and really doesn't care who he has to screw over to get there.

2)The lich has had his demon minion possess the rightful king's half brother, who deposed his brother and assumed the throne. So now the lich has more or less direct control of stuff. It's not an "evil kingdom" scenario... the lich gets no particular benefit out of making life suck... but he can and will make life suck if it becomes beneficial later. We can assume generally similar scenarios in numerous other cultures.

3)The true king hangs in druid circles now and eats a lot of mushrooms. He's under the tutelage of one druid with nasty apocalyptic visions. They see the end of the world coming and want to stop it. It may be that they are seeing the lich trying to go all-powerful, or there may be some second threat.

4)The lich has manipulated things so the monstrous humanoids and goblin nations are at war with the humanoid nations. The two factions were never on truly friendly terms, but things are really breaking down now. The lich would want to do this for two reasons. The first is that united, the humanoid and goblin nations would pose a threat to his own kingdom. The second is that he has greater influence with the humanoids and wants to access a nexus of magical energies in the goblin nations.

5)There is a council of gnomes far away, who disapprove, but do not interfere.

Now, I'm starting this at first level... so none of that will be all that useful until about sixth level. X_X. My real priority is detailing the starting city, some fun stuff to do to pass the time and level up, and a way to get them eventually involved in the conflict between the old nobility and the new regime (see 2). Actually, having the coup happen later in the game might be a nice idea. Even better if I can get the PCs to side with the usurper.

I don't know... mostly just brainstorming. What are your thoughts? Am I going into too much detail for stuff I won't be using yet? What should I prep for the first few adventures?

[littleangryman]

Blasted boards ate my reply -_-
Anyway, sounds great. If you want my two cents, here goes.
-The story, with the king, the brother, the lich, and so on. Possibly start the story with nothing amiss. The party are standard adventurers, doing standard 1st level things like low-end tomb raids. Meanwhile, all this business with the brother siezing the throne goes on in the background, quite distant from the PCs who probably (depending on their background) may or may not care.
-The war. You can engineer the war and the PCs getting involved all at once, by having the PCs get contacted by a "royal" agent, with a request to clear out a nest of goblinoid "brigands" and promising a hefty reward. What adventuring party hasn't gotten a job like that at some point? All that's needed afterward is some way (possibly via either the gnomes or the druids) for the PCs to discover they've been had, and voila.

Just couple of thoughts, use 'em if you like 'em.