in a 4 month game, i will build univ and arch to lvl 4, then build lvl 2 inf barracks, then mil acad lvl 2, build fort lvl 2, then trade lvl 2, then 100 sword, every time you log in, 2 times a day, build lumber, mines, granaries after you make 100 sword, then more inf barracks, mil acad, when you reach 1k in swords, use army to attack lvl 1 and 2 fortresses that are more or less unprotected, use the loot to build lvl 3 fortress, mil arch, and fortification, build centralization when you can afford, work in more univ and arch, adding beauracracy, armor, melee, and range when you can, hiring a diverse blend of spears, archers, lite cavalry and swords gives you options, don't forget to work in tactics, cartography, spies and border forts, mil medicine is important, medicine helps with population growth....thats how i start....but how some dudes grow huge in imperia is still a mystery to me....and i have played for over a year now...
just build up gran/med/ buro, and make lots of iron mines, dont make any stone, just wood, and lots of iron. As soon as the iron hits 5+ gold, you ll grow exponantionally!!