Looking for a How-To guide for building a mod.

Ive scoured ECF and the web in general for a "friendly" how-to guide for mod building.

I've got a concept for a mod in a custom enclosure that I want to try, but don't know where to begin. I don't mind learning about circuitry as I go, I just need a guide to tell me to "Buy X and Y and solder Z to A. Does anything like this exist that would help me in my project?

Thanks