And here are other things to consider.

9) Where does the food come from?

Your nation—or city-state, or confederacy, or alliance, or whatever—needs a breadbasket. If the people are living in a city, then they’ll need to arrange to have food transported in from outside. That could mean farmers bringing it in each day, in which case the farmers can’t live too far from the city. It could mean magic, though that should have a high cost. It could mean that the food is brought in and distributed equally from some central warehouse, which still leaves the problem of bringing it in.
This may seem like a minor matter. I’ve read any number of fantasies set in cities where food appeared magically in the markets or on the table. Well, the problem is that it’s not a minor matter. It’s a very basic one, which is different. You should consider it, even if your characters are so aristocratic that they just don’t deign to notice. That way, if things happen in the story that influence the farmland, like an invasion, you know when to bring in the impact to the main storyline.
Maybe it’s not agriculture, though. Maybe it’s hunting and foraging that supports your tribe. The one problem here is that in this case the society can’t be too large, or they would run out of animals pretty soon (or just drive them away, since why should deer or elk or wild cattle come too near a noisy human encampment?) The people will most likely need to be nomadic, or subsist mostly on plentiful plants, with meat added in as a nice little aside. Don’t glamorize this life, either, any more than you should life on a farm. Hunting is damn hard work, and a successful hunt can take days.
But you don’t want either a hunter-gatherer society or a farming one, let’s say. You put your city by the sea. Fish still have to be caught, shellfish still have to be gathered, kelp (or the equivalent) still has to be harvested. Again, keep an eye on the food situation. If the enemy is blockading the harbor, how are the fishing boats getting in and out? If a huge storm comes sallying along, does the city go on rations until the boats are repaired? Probably not, but they might be eating a lot of salted and dried fish and whatever food can be gathered in-shore until they are.
Always, always consider how people fill their bellies. Take away the food, and most characters should get far more interested in that than they are in who poisoned the President.

10) Where does the money come from?

Yes, most people hate tax collectors. Fantasy authors must hate them even more than most people, since they almost never portray them.
Your brave new world may not need tax collectors. However, if it has a money base and not a trade-and-barter system, this money needs to be minted somewhere, it needs to come from somewhere, and it needs to be gathered by your government to be used for projects like roads, wars, sewers (if they have the technology for that), nice buildings for the people in charge, and so on. Possibly even more important than all of these, it needs a guarantee. Why do people trust that the silver coins with the current Parliament leader’s face on them have value? If it’s not your government backing the mint, it had better be someone, or things will get messy quickly. (Although it could be wildly fun to read about a fantasy run on the banks or recession, done right).
The guarantee works in other ways, too. Say that you have a society on the fringe of anarchy, where hardly anyone trusts the government and outlaws are running wild. Would you really expect the outlaws to refrain from attacking the tax caravans, or however else the money is coming to the government? Of course not. If they can do it right, here’s a bunch of free money that they certainly don’t have to pay taxes on, conveniently gathered in one place.
Where does the money get stored? I hope you have good security measures, or good mages, to protect it. Sometimes treasuries seem to be huge hoards of coins that government officials (or monarchs, in those stories) walk in and out of at will, leaving me sorely puzzled. I wonder why some thief doesn’t just pretend to be a messenger, stroll through, and help himself to some treasure. If the hoard’s as big as all that, and the protection that casual, it could be a long time before anyone noticed.
Why is the metal the money is made of valuable? There are other mediums of exchange than metal, and in a world where gold or silver is very common, it would make sense to mold them out of something else. Perhaps your society uses gemstones, judged to the exact value. A small ruby could buy you a fine horse, or maybe just a sack of potatoes if rubies are common, too. Perhaps your society does use a direct trade-and-barter system. “Give me an egg, and I’ll tell you your future.” Perhaps magic itself is the medium of exchange. If mages are born with certain specific talents, why shouldn’t one who wants to get his future read offer to levitate huge stone blocks and build a house for someone whose only talent is divination? (This will work better with less centralized governments, of course).
Who controls the material that makes the money? It would be a nice joke if Parliament woke up one morning and found that one member “innocently” owned all the silver mines now.

11) What is your society’s image of itself?

This is one that does get more tending to, though it doesn’t receive enough; many authors create a simple picture and are content to let it go. You should be more thorough. And yes, I am a fan of world-building. Not necessarily of world-building being brought into the story, because infodumps= yeeurgh from me, but because the author should know the answer to a sudden question if it arises. And because I love a sense of place, which is another reason that I prefer not to walk through cardboard fantasylands.
Your society’s self-image will influence the way that your government leaders act, the rhetoric they use, the images they draw on when dealing with foreign powers or trying to inspire people to vote for them, perhaps even their magic. Jefferson’s picture of America and the people who were important in it is certainly much different than the one most Americans have now. ‘A nation of small farmers’ might still be an ideal for some people, but for even more people, something like the melting pot is. Or the idea of the United States as the most powerful country in the world, one reason that a lot of other nations think of this country as arrogant. Or a nation of small and scattered pieces, only some of which are actually important to the people in power. If you have a nation as large and varied in background as the U.S, conflicting images of it are possible. If your nation is smaller and its people share a common cultural background, a language, a religion, then the image should be more cohesive.
The government leaders should dream of a future, and it shouldn’t be necessarily based only on the dreams of certain individuals. For one thing, the society might not agree with them, and they’ll have to present a prettier picture than “I dream of being in power forever and making lots of money.” For another, even if your government ruthlessly corrupts everyone in touches, it’s likely that it still strives to present an image that isn’t corrupt, to convince people it’s doing its job, to lure in fresh blood by showing some happy and golden façade. Dictatorships and similar societies are the only examples I can think of that might get away with being all about brutal power, and they usually get toppled a lot faster than governments that make attempts to prettify themselves and make people smile in their sleep. Besides, as we’ve discussed before, brutal power is boring. I’ll add in something else here: It’s a lot likelier to make your villains into black hats or Dark Lords without redeeming features, if you insist that they openly torture people in the streets and laugh about it.

12) What kinds of demographics do you have?

In a way, this is genealogy for your society. You don’t need to work out every facet of the culture yet. I’ll talk about ways to do that in a later post (partially because I know that if I start talking about it now, I will never stop; I enjoy creating myths and fairy tales and metaphors and poetry and languages more than any other part of world-building). But there are other things you should know.
What’s the pattern of the generations in your society? Was there a baby boom? A baby bust? A generation that was very small because of a famine/plague/war/civil war/all of these attacking at once? Was there one generation that was very large, but the population stayed essentially the same because so many of them left the country for whatever reason? If you’re not dealing with a monarchy, you can’t automatically assume some of the things that medieval fantasists tend to take for granted, like large peasant families, smaller noble families, high infant mortality rates, and so on. Your world might look entirely different. It’s your responsibility to know that.
Is your population more rural or urban? Some of the decisions you made for question nine, about where the food comes from, might affect you here, but not necessarily. What are the largest minorities in your society, or does it have them at all? Do these minorities live segregated? (It’s remarkable how many of them do in many fantasies—segregated by their own sense of self-righteousness, if nothing else. If I read about one more group of perfect, persecuted witches I am going to scream). What are the racial ratios, the species ratios, the ratios of mages to non-mages? Those things can make an incredible difference. I’m writing a novel currently in which magic is two-tiered, with the only people who can actually gather it in born in about 1 out of 10,000 births. It’s…interesting.
If your races and species are more mixed, how many mixed-blood children are born? How are those half-breeds regarded? Consider skipping the half-breed angst and going straight into the government considering them as people like anyone else, or no one caring what their blood is like as long as they have enough money. If you have a society that doesn’t give a flying damn about bloodlines, like one where aristocracy never developed, it would make more sense to treat them in accordance with those ideals than as completely separate individuals.
And that finishes government, I think. Next one’s on culture.