Author Starts Three Mini-Layouts at Once

With the start of mini-model train layout I am out looking for how-to's and some inspiration for my 3 by 3' HOn30 layout. There are a lot of details that I am still up-in-the-air about, but there are a few details that I am sure that I want include:

1. There will be at least one over and under section
2. The railway will make use of the motive power I already have on hand. The railway will feature steam and early diesel engines
3. The layout will model rural america in the late twenties to early thirties
4. Include at least one train stop