Ok, I have played the game twice now, my second file is midway through, and I think I am going to lose.
I have no idea how to progress through the epochs, I have no idea what settlements are for, why citizens have the option to populate.....and I can't find an FAQ.
Anyone?

Have you tried playing the tutorials (called "learning scenarios")? IIRC, they give you quite a good base knowledge to play the game.
If/When you're done with that, Empire Earth Heaven is a good place to browse.

To answer the second one first, settlements are kinda like warehouses in other games. The citizens will bring their harvest there, so make it good and close to the resource. ALSO - you can and should populate your settlements. You can do this in 3 stages, 5, 15, and 50 (you have to do one at a time, so if you send 15 there, you'll see 10 standing around when you're done, just send 'em again). This upgrades the capability of the settlement and value of the collected resource. When you have at least 5, you can also produce citizens at the settlement. Do this as soon as you reasonably can - it's nice to set the rally point for a wood settlement right in the woods!
Citizens are an important resource in this game!
Oh yeah, when you build farms you should also fully populate the silo in the middle with 8 citizens. Don't stop at one farm, BTW.
Now, once you have a few settlements rolling and your income coming in, click on any upgraded settlement and in the bottom left you will possibly see the option to advance to the next epoch (in Roman numerals). If you don't have enough resources, it will be greyed out. You usually need lots, so keep collecting and keep populating the settlements!
And above all, don't get frustrated when learning. Each game you should get better... the things that frustrate you in the beginning will probably be the things you love about the game later (the AI, mostly).

Quite a helpful post, +1 rep for it.
However, a small addition.
You also have to have 2 buildings built in the current era. While it's natural in the epoch you start in, later, when you don't build as much, you may have to pay attention to this. Walls and towers, of course, don't count.

Thanks for adding that! I suspected as much, when I checked the strategy guide I have, I only noted resource amounts to advance... so I wasn't sure.

That leads me to my second question....is the Prima guide for the base game+expansioan worth it? I found a used copy online for like $5, and was wondering if it would help.
The reason I am being so meticulous is because *I* considar Empire Earth and "event game" for me in that I plan on investing quite a bit of time into it, if that makes any sense.
I am a very enthusiastic fan of human development and history, so the scope of this game is just absolutely breathtaking.
A modern day remake would kick ASS, though I find the game quite playable as-is.

Personally, I don't use it much but I haven't ever really been a strategy guide guy, unless some campaign seems really crazy difficult...
Now that I skim it again, yeah I think you'd like it. There's a good overview of game mechanics plus stats, civilization advantages, multiplayer tips and so on. Even a few pages on "The Theory of Scenario Design". I really should read through and get some custom civilizations set up. :)

If you hover your mouse over a post, in the top right corner, you'll see the text "Rate this post". Next to that, you have a + and a - sign to rate up or down that post.

No, it isn't; substraction is a good thing if used correctly. For example, remember Ezri the infamous spammer(bot)? His posts typically got showered with - rep.
It is a good community, so memebrs don't tend to give +s and -s just based on personal liking and hatred.
Also, it is a way to show to the community which threads are really good and which ones are to be avoided: when you open a thread, the first post will bear the text "high rated" in the top right corner (for examples, see or [url=http://www.gog.com/en/forum/general/free_games_list_and_3rd_party_mods/_/1]here. In the same way, bad threads' first posts are marked with "low rated" (sorry, I can give no example right now, as all the ones I remember have been deleted, due to being spam).

Mine has gone down 5-6.

I think that's due to your post about Strategy First titles and their developers not getting the money.

Lol, if so, a system where messengers get "penalized" for telling the truth is a little flawed, don't you think?

Nope. You have to realize certain "truths" are quite subjective... I'm not going to get into an argument with you over that "truth" either here or there, and most certainly not -rep you for it, but you should consider that if EVERYONE goes against one, maybe that one should think about his/her point's acceptability.