I am working wit that book right now. I am also working off this list of links provided by Stumbo.
Some noob from Alaska
I have taken a series of lessons and have the luxury of having a guitar player who taught music come to my house to play with.
I have the same questions. I'm guessing it will take me months to master the book material as I have a multi pronged approach to learning the bass. I'm not trying to learn songs per say. I am learning to read music and I am studying music theory. My ultimate goal is to be able to pick up my bass and play along with just about any music and sound good. I want to be able to read music as good as I can read the written word.
My best answer at this point is that progress is up to the individual and will vary wildly. Practice, study and play. I'm finding that playing live with a guitar player is a big confidence booster and it keeps me from getting bored.
We're in for the long haul..Like Charlie Daniels said..Its a long road and a little wheel...It'll take a lot of turns to get there.