OK...sounds like it won't be too complicated !!  Thanks for your help.  Someone else recommended the MRC 7000; I'll see if I can find one on eBay...

I'm not going to even pretend to know what I am doing when it comes to model railroading. We built this Christmas village and it has three separate train tracks on it that are independent of each other. I want to add sound to the setup and I would like to be able to control all 3 trains from one control box if that is possible.....

Can anyone help??   

OK....thanks for the info; I will check out eBay...

I have three Bachmann train sets; the Village Express (HO); the Kinkade Christmas Express (On30)  and the Wonderland Express (On30) What transformer can I get that will control all 3 trains?  Also, how can I add sound to these trains?