the preferred technique for a waterstone is so intuitive that you're served best by buying one and using it on a couple cheap kitchen knives. you'll learn more than you will any other way, and get past the part where you are learning faster.
The techniques are most obvious with a coarse(ish) stone (something around 800-1200 grit) and fairly soft carbon steel .. old cheap kitchen knives are fine practice pieces.
just keep the stone wet, work up a slurry (paste) and work on that.. edge first. it's messy, working over the kitchen sink is convenient, or setting up a dedicated work area, with a water tub and good light..
you learn to sharpen by putting steel on the rock. you can learn HOW from a dvd.. but your eyes learn, not your hands.
and once your hands know, you don't need a dvd. i'm clumsy about tools, not a natural craftsman.. and i'm *quite acceptable* with a stone and a piece of steel.
The first 5 years of practice were the hard ones..
Remember, a waterstone has mud all over your edge when you're using it.. if you don't FEEL what you're doing, you're going to be nervous and uncertain and take little pleasure in it.. precision follows FEELING it..
a trick worth trying, if you're sharpening 'freehand' .. ie, stone in one hand and knife in the other.. is wear a kevlar (butchers/ filet) glove on your stone-holding hand.
it lets you be a little less concerned with safety while you're trying to concentrate on being IN the edge..