I have played the Germans since I first started this game, and I'm telling you now that the first thing you need is patience. The Germans can be a little difficult for some people to get used to (myself included) but they are well worth the trouble.
Basically, here it is:
1. The Pros: Strong economy in later ages, tough military in Fortress Age, early raiding possible (2 Uhlan and 9 x-bow shipment), free cavalry (Uhlans come with every shipment), good siege. (Landsknecht and Dopps have a field day in enemy towns.)
2. Cons: Slower early economy, only basic troops in Age 2 (Dopps aren't worth it so early), some units are expensive, and most units are highly specialized. (e.g. War Wagons)
3. Everything else: The Germans are totally capable of rushing, but I personally would not recommend it. It is much better to simply stave off any opponents' rushes, raid their economy, and build up your real attack force in age 3. The reason I don't like to rush so much with the Germs any more is that their troops are really only suited for defense. Pikes and x-bows are the only thing they have to rely on, and thee units are not the greatest in early ages. Rushing is perfectly viable, however, so feel free if you think you can pull it off; just be prepared for the worst if it doesn't work.
A more conventional strategy would be to get to Age 3 relatively soon and begin building up your forces for a kind-of Fortress Age rush. (A good example of this is the German Semi-Fast Fortress, where you build up an army to defend before you age up.) Once you reach the Fortress Age, you can either build x-bows and Dopps to counter infantry, War Wagons to counter cavalry (A necessity against France!), or Uhlans and x-bows to counter enemy x-bows or other ranged units.
A personal favorite of mine involves getting to age 3 very quickly and then purchasing a shipment of mercenaries (A Merc-FF.) to supplement my early army. Believe me, 10 Landsknecht can turn the tide quite easily if gotten fast enough. (One of Germany's good points: the best, and I mean best mercenaries in the game!) If the enemy is going heavy on infantry, you can get 13 Jaegers instead, or Hackapells if they have artillery.
If your enemy is unlucky enough to survive till age 4, then you can easily out-boom him (unless he's Portugese or British) with your Settler Wagons + Villies. Also, Guard Doppelsoldners and Neddle-Gunners are highly effective at this point.
In summary, the Germans are a very versatile civilization with many great ways of playing them. I think you'll have a lot of fun with them. The only civs you have to watch out for are the Ottos, for their early rush, and the Dutch, who are un-rushable for you because of their skirms.
Hope this helped. Have fun!