I'm a literature student and I'd like to be able to annotate literary texts (originally stored in HTML or as text files) on a word-by-word or line-by-line basis. I hear databases like mySQL or SQLite would be good ways to do this sort of thing, but I don't really know where to start.

I'm comfortable with the linux command-line, and have done some HTML/CSS work in the past, so I feel unintimidated by databases and things...I just don't know what to start doing.