Yeah, a good introductory article on basic spectroscopy.
Doesn't go into the "science" but hopefully enough "Ohh Ahh" to encourage amateurs to give spectroscopy a go.
A grating can be used "in the converging beam" in almost any telescope (>f5 preferred to minimise aberrations.)
Paton Hawksley, who supply the Star Analyser gratings has an on-line calculator to assist in evaluating the distance the grating should be placed in front of the camera for optimum results.
http://www.patonhawksley.co.uk/calculator/