Hey guys, I'm looking into integrating kettlebells and sandbags into my workouts with one of my friends, and we are both looking into spending some money buying this Invincible Fitness: Basic Training ebook off of http://www.invinciblefitness.com. The guys seems pretty legit and he is uploading videos to youtube that help with the workouts at www.youtube.com/ericinvincible.
Yes get the kettlebells but hold off on the books and vids. You can look up a lot on youtube on kettlebells and workouts so that might save you some money. Maybe after you search through youtube for a while, then you might have a better idea on who else is out there with books that can help you.
Here are some KB sites
and where I got mine: http://www.muscledriverusa.com/