Read "Wiring for DCC." The information container here applies to DC also.
http://www.wiringfordcc.com
Any well-stocked hobby shop that sells trains should have a book rack, and at least one of the books should be on the topic of layout wiring. Atlas, Kalmbach, and other publishers have released several books over the years on layout wiring.
The first question is going to be DC or DCC.
Have you tried any of the available books about layout wiring? If not, you should at least try one of them. I had similar issues about benchwork, and I found reading about it definitely helped.
It takes an iron man to play with a toy iron horse.
NEED HELP in Wisconsin with the wireing of my 4' by 12' layout, do NOT understand electrical wireing!1 have made 4 attempts to wire tracks and each one has proven more a problem with the last one. Need someone to come to my home view my layout and analize what is wrong. Am willing to have someone wire it for me and pay them for the service. Been over 2 years in the making and the grandkids are getting upset with there grandpa.
Thanks