I'm afraid there is no comprehensive guide *yet*. Portablising has always been a sort of "struggle your way to success" type hobby, so all we really have are a series of guides about specific aspects of the build that you'll need to string together yourself. I can, however, point you to the basic reading materials to get started.
The documentation, pinouts, and some wiring guides are available on the
4layertech pages for each of the individual boards that are used in conjunction with the Ashida basic PCB set. The information provided is very specific to each product, but contains everything needed to get them wired and working.
For Wii specific info, have a gander at the
Wii Guide section. Specifically Wii Motherboard Anatomy 101, the Revision Identification Guide, and The Definitive Trimming Guide threads. These contain the information framework you'll need. In addition, I'd have a read of
Ginger's Trimming and Troubleshooting FAQ. Afaik it's still accurate and covers a great many potential issues you may run into.
For general information on soldering and electronic principles, check out
Shank's Electronics 101 thread. I'd also read
Ginger's General Tools And Materials Guide thread for a list of commonly used tools and materials..... funnily enough.
If you read through the basic materials and can come up with specific questions for things you don't understand, or want advice about, we'll do our best to help you out. Just be aware that knowledgeable members aren't always free, so some questions may take some time to be answered. If you want/need more realtime help, our discord is pretty active.
