Not you as well!
You could start
here, where there's a list of some of the research that's been done. Most of the links are, I believe, to articles published in "Nature", which as a peer-reviewed science journal is probably about as high a standard of proof as is likely to be available. Unfortunately that means you may need a subscription to read them.
Otherwise, it's covered in a number of books too, perhaps Ben Goldacre's "Bad Science" though I'm not certain. I know he did some stuff about security people dowsing for firearms or something like that quite a while back. Brian Regal covers it in "Pseudoscience: A Critical Encyclopedia". Possibly not as reliable as Nature though.
James Randi did quite a few trials, at least some of which are on youtube, where dowsers attempted to demonstrate their ability. He was trying to be as scientific as possible whilst perhaps compromising due to the requirements of making television programmes, but I think is considered to have been more than generous in terms of allowing the dowsers the opportunity to produce a positive result (or alternatively, in giving them more than enough rope).
James