I'm planning on a small 4x4 HO layout.  I know that this is the smallest space in which I can put an HO layout and was wondering if I can do 2 train operation if I use a couple of short sidings with short trains.  I'd like to run the trains separately, using the sidings to hold one train while the other one runs.  I know that I'll have to use short stock.  Can anyone tell me if it's possible and if so where I can find detailed instructions to wire it correctly?
Thanks much!