Good idea, i would love to play such a game and have been looking out for one since going android 2 years back. please make sure you make it for appslib (tablet market) too
there is unlikely to be a tutorial for making a city builder as this is a niche market and if there were such a tutorial there would be plenty of such games also meaning you would make no money from yours. However there may be one for something similar, think tower defense game, side scrolling shooter, suduko, hangman, that sort of thing. I did see a 2d graphics tutorial somewhere for android, don’t recall where, you will have to look it up.
Hope that was more helpful than ‘rofl’!
Looking forward to playing your game.
-G