In our old forum i had a very long list of tips and advice, unfortuanatly it hasn't been moved across!
I said in short:
1) Build crannies, teutons take 1/3 of all hidden resources ontop of whatever isnt hidden! Gaul crannies hold twice as much!
2) To aid defensive troops build up your wall.
3) Always ensure your wheat production is high to allow continuous expansion and large armies!
4) Stay active and keep up population growth, this way you stay in the alliance and have less chance of being attacked
5) Have fun! If you have any questions about the game just post in the relevent forum or message one of the leaders such as myslef, Ichbein, Kylic, etc!