Jamie's been asking for some thoughts on what it takes to do this--statistics backgrounds, etc. I should say that I'm doing this, for the most part, the hard way, because 1) My database is too large to start out using most tools I know of, including I think the R text-mining package, and 2) I want to understand how it works better. I don't think I'm going to do the software review thing here, but there are what look like a lot of promising leads at an American Studies blog.
As for whether the courses exist, I think they do from place to place: Stephen Ramsay says he's taught one at Nebraska for years.
It's easy to follow a few of these links and quickly end up drinking from a firehose of information. I get two initial impressions: 1) English is ahead of history on this; 2) there are a lot of highly developed applications for doing similar things with text analysis. The advantage is that it's leading me to think more carefully about how my applications are different than other people's.