<<Get a copy of a how to book on wiring a layout. Kalmbach has How to Wire
Your Model Railroad, by Linn H Westcott (out of print). Carstens has
Electrical Handbook for Model Railroads, Vol.1 & 2, by Paul Mallery. These
are generic books and cover more than just train control.
Follow the directions for wiring a DC layout. That will cover 99% of your
questions including gaps, wyes, and reverse loops.>>
Glenn has given you a very good idea here. Block wiring is block wiring.
The experts from an earlier era (Westcott and Mallory in particular) break
down wiring how-to's to the basics so folks can really understand what they
need to do.