Hi Ryan,
I played Civ for years (I own Civ 2, 3 & 4, but Civ 2 has always been my favourite) and bought Aoe3 last August or so. I didn't really understand how an RTS worked until I played the game. I played offline for about a day and then jumped online. Others disagree but I think this was the best route for me anyway. In Civ you play against the AI and have a fun time, but in AOE it quickly becomes repetitive, and AOE lends itself better to multiplayer formats. Plus I think as a TBS player you will pick up a lot of bad habits learning against the AI.
Personally I had a very hard time adjusting to RTS. Like you my first instinct was to just "bring everything" into battle figuring that should do the trick. For a variety of reasons that is not always the optimum strategy. There is this horrible RTS thing called "micro" which can make or break your game at times. Whether you will learn faster than I did I can't really say. *grin* I advise you to just jump into some games- online- and see what you think. I can tell you now that Civ is not the same for me anymore. I much prefer AOE even if I will never be as strong a player as I was in Civ.
You aren't protecting your buildings in the manner that you would protect cities in Civ. For one thing your buildings are generally built close to your Town Center, which has its own attack when settlers are garrisoned inside it. It will take some time to take down a building (and during this time the Town Center or outposts that you have placed will be firing upon the enemy army) and during that time your army can come over. If instead you spread your army thin, surrounding your city, you would find that any army that showed up to try to kill some buildings isn't going to be postponed by a few guards anyway. You will need your entire army.
You mostly care about your villagers and try to defend them more than your buildings. If they die you have nothing to gather resources.
Your army should not be stationary like it is in Civ. You should be walking around, seeing what your opponent is up to, harrassing him, getting treasure, whatever. There are no peace treaties here to buy you time, it is always constant war heh.
There is an AOE3 strats list here and a TWC one here if you have The Warchiefs expansion pack. [This message has been edited by wreckoning (edited 05-03-2007 @ 07:48 PM).]