Today I called Oasis (http://www.oasiscd.com/) and got a quote. Then I called Vito (www.iamvito.com) and gave him the go-ahead to send my CD to Mark Dann (http://www.markdannrecording.com/) for mastering.
Listening to the pre-mastered CD, I'm feeling very proud of myself and grateful for all the wonderful talent (other people's) that went into the making of it. And also hoping that some of the flaws I hear in my voice and guitar will be lessened in the process of mastering, which I still don't understand what it is but am led to believe that it is a sort of magic incantation that is muttered over the CD and makes it "shimmer." It all sounds like something out of Harry Potter, but whatever works.
Now I'm planning my CD release party and wondering what to do next. (Besides try to recoup the money I laid out.)