Need some help

If you are only planning on running one train, one set of leads may suffice. A better idea would be to hook the leads to several different spots around the layout. If you are planning on running more than one train at a time you will need to set up isolated power blocks that can be switched from one control (power pack) to another. There are many books available on the subject.
HOrailroading

Steve,
Are you using 'sectional' or 'flex' trackage? If you solder the entire railroad together, you might run into expansion issues. I use flex and have soldered the curves together, and most of the electical blocks. I do have some normal rail joiners yet, but there is a seperate feeder for each section of non-soldered track in a block This is on a 25 by 20 layout. If you are using sectional trackage on a 4 by 8, I would make sure you use 'new' rail joiners(they get 'loose' from all of that 'test' fitting. Then attach your power to the 'terminal' track. With new 'tight' rail joiners, there should be no electrical voltage loss on a small layout. If you still want to solder, you might want to solder the junction of the straight/curved trackage as this is where derailments happen many times. As far as 'rail expansion' goes, I had problems on an old 8 by 13 ft layout with some curves 'popping' the first summer. The current layout has much longer runs, and one would expect that the problem might be worse. When I layed the track, I used a #11 Xacto blade as a spacer between the rails at each joint. This was to allow 'expansion'. Worked fine, but about 2 years later, I started to run in to voltage drop issues, and wound up soldering rail joiners or adding feeders to each piece of flex track(the 'drop' was in a long tunnel - figures).
Jim Bernier
Steve Gibs> Hello everyone, I first thank you for taking time out to read and hopefully

On a 4'x8' layout, a single set of leads should be sufficient, and you probably don't need to solder, either. Just make sure that the rail joiners are tight fitting.