I am planning my first real HO layout. I would like an oval within an oval connected by 4 turnouts. The ultimate goal being the ability to run 2 trains at once. After reading up on different wiring schemes it seems the easiest is common rail. I have multiple power packs that I can use. I must setup the same rail as "common" on both ovals. My question concerns the gaps. It seems like I will need 4 insulated gaps (one on each turnout). These gaps must be located on the control rail. Is there anything I am missing? I have read about "blocks" and other control mechanisms but they just seem confusing and maybe unnecessary. Any help or advice would be appreciated. I have not found any detail "white" papers concerning this on the internet. I just don't want to ruin my Dad's trains that he left me. Thanks.