A few newbie questions.

[Aezeal]

Trading a a main strategy really isn't a viable strategy.
It can help you from time to time but it won't win games, battles or wars.

Don't start with MA Ulm.

[Tuidjy]

Duncan_Frost, stay away from MA Ulm. If you want to be a trading nation,
EA Ulm or AA Arcoscephale are much better choices. These are real nations...
MA Ulm is a sad joke.

[Duncan_Frost]

Ugh. If not Ulm, who would you recommend as a good nation to start off with? Just for practice in SP. In the demo, I've taken a liking to Arcosphale. Having flying units in the PD is fun, no matter how useless they are.

[ComTrav]

You'll find MA Ulm is a little contreversial on these boards; it seems to be a "love it/hate it" nation. It's fine for SP, though.

For SP, when I was just learning the game, here are some nations I found useful:
-Any country with strong national troops is more amenable to newbies imo. Countries with weak national troops that rely heavily on mages/commanders/special summons can be harder to get working (Agartha, Bandar Log, etc.)
-Since you mentioned flyers, I figured I'd mention Caelum, where almost everything flies. EA Caelum is great to play around with high level evocations, too. When learning the game its easier to focus on one or two schools per game.
-However, when you're ready to play with LOTS of different magic, Tie'n Ch'i (I played EA) was very useful to me when learning the magic system, because of its ridiculous magic diversity. It has a solid troop selection, too. Maybe play your 3rd or 4th big SP game as TC, the amount of magic options available to them are overwhelming at first.
-Someone will mention Niefelheim, and its probably the best bet for a bless strategy. Take high bless, build frost giants, profit.

[Duncan_Frost]

One of my favourite spells in the demo is Cross-Breeding, so Blood. Who's a good blood nation? And what's a blood economy?

[ComTrav]

"Blood economy" is the collection of blood slaves. It's easier to capture blood slaves in high population provinces, but blood hunting increases unrest and reduces population. Hence, a "blood economy" is fundamentally opposed to a "gold economy".

The big blood nations are EA/LA Mictlan and Lanka, although lots of nations have smaller blood picks (the "'heims", LA Marignon and Ulm, Pangea, come to mind)

[Tuidjy]

Duncan, if you like Arcoscephale, stick with them. They are a fine nation.
Not one of the powerhouses, depending on whom you ask, but a very strong nation.
I suggested them as a trading nation not because they have a forge bonus - they
do not - but because they have a great selection of magic, especially in the
Early Age, and excel at all three types of magic searching. By the way, make
sure you have A4 (four levels of Air magic) on your pretender to exploit the
Oreiads fully. They do not look like thugs, but they can be.