Ruby on Rails: Up and Running sqllite error

I have the book, "Ruby on Rails: Up and Running." I followed all the instructions up to Page 12 (defining the index method), but now the browser says,

"This error occurred while loading the following files:
sqlite3"

I googled this error and came up with a random set of poorly explained suggestions that do not work.

With all this canned installation stuff and very little explanation of what it does, the reader is completely lost if one step is wrong.

What can I do about this sqllite error? As in, "exactly what should I type," not "try reinstalling everything."

More to the point, how can anybody debug things when any one of these canned installation steps doesn't work?

I am only up to Page 12, and now I am thinking I have to go buy another RoR book.