Newbie game? Go for the bloodsac tactic. Teach them that a properly executed blood sacrifice tactic is very very dangerous.
If you have sailing, play around with that in a SP game. I played LA Atlantis, and there I learned how immensely powerful it can be. (You can skip one sea province, even if your army is already underwater. As sea provinces tend to have a lot of connections to other provinces (which is something that makes it hard for water nations to keep their dom up) you can really use this to your advantage.
Personally, I would go heavily for blood. You can bloodhunt like crazy, blood is crazy strong. (Gives communions, good summonables, reasonable SC's if you get there first(*), good combat magic). The only problem with blood magic is that you can never ever have enough blood slaves. (NEVER) So you tend to lag research wise, as you need your mages to blood hunt. (A heavy blood nation that leads in research while still being able to wage war has probably already won).
*: Never mind the SC's only get them if you have blood slaves to spare and what to deny them to others.
http://dom3.servegame.com/wiki/Fallen_Angel Get those. f3d3b3 yes please
. Rush for those. No upkeep, sacred, can bloodhunt, good stats... Nice
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(Of course, you could ignore me and go for the conjuration summons, also very good, but you probably need to build your pretender around summoning those).
LA marignon is very strong, access to almost all the paths except nature. (Harbringers give air). Blood, good mounted units as blockers, crossbows, sailing for raiding. Scouts.
I think I would go for n4e4 on the pretender (helps with the sacred mages, and late game sacred summons) dom10 and scales. Imprison the pretender for points (One downside, you only get to sitesearch with the pretender for N mage in very late. Rush blood for blood 7 to get access to death magic. Flood the world with blood sac, demons, or just get vampires, as your dominion is going to be everywhere, they are hard to get rid off. And 3 vampire lords can blood sabbath to get to d4 and cast darkness. So you don't even need to risk a 'expensive' skull staff into combat.