I don't have a layout guide, I do have a city anyone can see. I am almost to the 5 million mark which is probably going to be my max until more land opens up. 6 million does not seem possible because the higher population skyscrapers require more sewer, water, power, etc. I tear down regular skyscrapers and Parisian skyscrapers to build London, Tokyo, and epic buildings and my service needs continue to rise. I have 7 nuke power plants and random windmills in my city with no real place to put any more services. My GameCenter id is The_Answer_
I set my city up to minimize the amount of land taken up by roads. If you want the most growth there are really only two ways to run your roads. The horizontal or vertical methods will both work but if they open up another expansion like they did for the last one, the land to the right (opposite side of the grid from the airport), then the best road layout is like I have mine now. As they add more area, you will use 50 grid cubes for roads compared to 52 grid cubes for roads that will cover the same amount of your map. Sorry if I my explanation is a little confusing. Send me a friend request on GC and you can see how I have mine running
