Too big a game to tell you every thing, but in short for the stratagy map. You can ignore the senate. Dont worry too much about numbers as quality of troops matters much more. A resonable stratagy to start with is a centre of heavy foot troops ( hoplites are exelent mercenrys early in the game, get them in greece) may be 6-8 long javlins behine that line ( make sure you turn the skirmish mode off these as they will run as the ememy aproaches). with horses covering the left and right flank ( keep these set back from the main line then when the enermy charges your last troops in the line you can swing these behine them and attack at a charge. General in the middle behine javlins. Thats pritty standard but works well so it will get you going.
When considering what land to take, look for ports first (largest profit), proximity and number of enermys and finaly natural defences ( eg bridges)
Hope this helps, tryed to keep it general but if there is anything more you what to know give me a shout.
