A recommended starting point - I suggest looking over the standard wire color codes that I use in all of the products that involve any wiring. It really is the basis for creating bays that are what I fondly refer to as "self-documenting". Following a standard color code makes it easier for you to work on your project and to have others involved. It is just an important aspect that applies to any type of electronics bay or project.
Wiring Diagrams and Drill templates - Here you will find sled and bay schematics for dual deploy and L3 redundant dual deploy. The schematics are general and apply to any project that you would build. There are some specific ones also, that detail wiring for SMT Designs connectors. Lastly, there are drill templates for those producs here that require mounting to your own sleds and other equipment.
The How To's are guides for preparation of parts and kit assembly of the various components that you find here. You may find the The Basics section handy if you are new to electronics and need a bit more detail on how to solder connections. Of note, the final link in the How To's is Electronics Bay Design - Putting It All Together which outlines part lists and ideas for different bay designs and types.
Concepts is a bit of history, a bit of design philosophy, and a bit of future thought that I wanted to share with you. I hope you find it interesting.
Be sure to read SMT Designs' information on 3d Printed Rocketry Products