-by lord hamreditor, server na42 when it opens. (The server is just so you get a good idea of the age of this guide).
There are many ways to build your army. The best is using more archers than warriors, though some techniques are different. In this article, building your army will be explained in steps. These do not specify exactly what time/day you should have however many troops, but give new steps after old ones are finished. It's like completing your "Wealthy Society" quests, when, for example, you complete the 10000 wood/hour you get the 50000 wood/hour quest. As the steps progress, it will take more and more time to complete each one.
There are troop types to meet on each step. You may ask, "Should i get the archers 1st on this step or the pikemen?". Well, I reccommend using whatever resources are available at that time. If you have little iron, don't build swordsmen, but build pikemen. Have a lot of everything evenly? Then build archers. If you are in BP, however, you can't be attacked so get the offensive units first (we will come to that next).
I believe that you should have a proportion of offensive-defensive units. I classified these based on their atk/def points as well as their health. A swordsman is a highly defensive unit, so it should not be used exclusively in attacks. Cataphracts may be greater than cavalry in attack, but the cost/atk ratio is less worthwhile. Archers are essential becasue they may have little points, but they have RANGE. Note that these
numbers are what you add to the previous step, not your total numbers.
 Step One
50 workers, 400 warriors, 150 Pikes, 75 swords. You may be thinking "Oh, why do I need workers? I get enough during the start of the server to build a city." Buy the reality is, once you've built the city, you will need to transport resources to it in its early days. So I added some workers just in case. Warriors are fast, quick, and require no tech, so you should build these first to get a flat. Swordsmen are primarily defensive units and you are in BP, so there is no need for them. They just waste iron, which players in the first few days of the server mostly lack unless they have an iron city. Build them after all other troops of this step are completed.
 Step Two
This step comes after you did step one. Usually, I got here about 3 days from starting. Troop counts are: 50 workers, 2000 warriors, 500 pikemen, 500 swordsmen, 1000 archers. Though your archery is low at this point, you should still have some so that getting Valleys to boost your production is easier.
 Step Three
Once your BP expires, you should have finished this step. Counts are: 10000 warriors, 1000 pikemen, 1750 swordsmen, 5000 archers, and 75 transporters. Most players have a lot of archers in mid-game, but right now archers are too expensive and time-consuming. Furthermore , bigger players are likely to use you as a farm, so you need defensive units.
 Step Four
You should have completed this step in a week after your BP expires. 25k warrs, 5k Pikes, 5k swords, 17.5 k archers, 2.5k cavs, 500 trans, and 600 ballis. Now if you have your first as a lumber city and your second as an iron city transporters are vital.