Ok, so I can create, view, and delete branches in Git. Repo sees them, and knows which one you're on, in the various git-enabled directories (I think... I've only tested one additional branch in one directory. I wonder if it can track two different branches in two different directories?)
My current challenge is this... I know that I should be able to build an installable .apk that I can push to my phone to test any changes I make to the Phone or Contacts apps, but I currently only know how to build the entire installable rom. Since that takes five hours, I'm not hoping to have to do that in order to test my tweaks. I think there is a way to build *just* the apk of the current project (app directory, basically), and push that, so I'll need to read up on it.
I've got Eclipse installed, and the whole CyanogenMod project is imported into it, meaning I can see pretty much everything .java in the whole /android/system/ directory. Having stumbled my way through another installation of the SDK in Eclipse, I know that app-building is integrated into it. However, I seem to have... missed that part this time around, so I'll be tackling that shortly.
All in all, I have to say that the amount of actual 'get started as a noob right from scratch' documentation is dismal. Thats kinda the point of what I'm doing here... stumbling through it, and documenting. When its all said and done, I'll have something a bit more structured that walks through the steps. So far, I'd say the biggest thing is to be familiar with Git first. I feel like I breezed over it, and while I understand the basics, it was/is tricky learning how git and repo interact.
Now to *correctly* get Eclipse and the SDK configured so the projects can actually be worked on.