[thejeff]

My advice may be different from most, but I'd say don't focus too much, at least at first.

Start up random games, see what you can do with what you get handed. Figure out which ones you like. Play around with early game in a lot of different nations in all three eras.

Read the guides, as it sounds like you've done, and try out the ones that sound interesting. Often for me those only click when they're a different way of playing a nation I'm already familiar with.

Half my SP games get started because someone posts something here that makes me go, "That sounds really cool. I want to try it." (And most of them end when someone does the same for another nation)

But the key is to play around with a bunch of them and find what works well for you and keeps you interested.