Bachman Please help, I'm a Greenhorn!!!

[moodybluenitro]

How can I have one locomotive on a dual oval with a crossover and a few
switches stop while a second locomotive continues moving on ?
Oh, by the way, I only have one controller...

[SteamGene]

The BEST thing to do is to buy a book on basic wiring.  However,  the easiest thing to do is to set your layout up with two or more blocks.  "What is a block?" you ask.
A block is a section of track, isolated from the rest of the layout, with power directly to it. 
If you just want one locomotive running at a time, isolate the two loops.  Do this by buying a card of plastic insulating joiners and use those to connect the turnouts connecting the two loops.  Then run run your power leads to two switches which can be either on or off (Atlas makes some).  Wire them together (with the Atas ones you merely screw them together) and run leads from one to one loop and from the other to the other loop.  Turn on power to the inner loop and only the inner loop loco runs.  Turn power to the outer loop and only the outer loco runs.  Turn power to both loops and both run.
If you want the locomotives to cross over from one loop to the other while they are both running, you will need more blocks. 
Gene

[Jake]

You could do as gene said, or if the engines are DCC On-Board, you could get EZ-Command, it is a very nice entry level system, and doesn't require the extra wiring that blocking would.