I have a couple that I bought off of Amazon: The Kettlebell Goddess Workout--which I haven't used yet because it's pretty intense and I'm not there yet--and Kettlebells the Iron Core Way, Circuit 1. I've used Iron Core, and it's pretty good (although I find the instructor a bit annoying and she doesn't cue particularly well). The first time I used it I thought that it was really easy...until about two hours after I was finished, then, wow! I was sooo sore. I called my sister, who is a personal trainer, and told her that I couldn't go to the bathroom because it hurt so much to squat. She wasn't terribly sympathetic, but she did get a good laugh at my expense!
Also, there is no cool-down in Iron Core, and it's a 45-minute workout, so plan on adding several minutes to stretch out afterwards.