I don\'t want to rely on the one-click installer any more, and I want to learn how to install Ruby manually. Is there a resource for this?
I'd start with the one-click installer, probably by taking a good look inside the source on RubyForge (disclaimer, I haven't actually done this...). These guys clearly know how to build Ruby on Windows from source, so I'd be inclined to see how they did it.
Beyond that, did you know you can download the 1.8.7 Windows binary from the ruby-lang.org downloads page? That page also has the current stable 1.8.7 source