When it comes to making pizza dough from scratch, there are two pretty big hurdles to pass in particular, so as not to end up with a very doughy, and a not-so-very-good crust. The first major hurdle is working with the yeast itself: too cold and the yeast won't activate, whereas too hot actually "kills" it. As could be gleaned from my yeast packet, if the water itself is far too hot but not hot enough to kill the yeast, it's best to mix the yeast into the flour; otherwise, it could be dissolved straight into the liquid. (By the way, for more fun reading on this particular fungi, click here.) The second hurdle is overworking the dough to the point where it will never rise; just think "elastic" and "springy" as adjectives you want your dough to be described as.
I acknowledge I've never actually made pizza dough before and have once again (this time, with much inspiration from this site) come up with a few techniques that yielded a result far better than my own expectations, especially as I don't have a cooking thermometer nor have had much luck with doughs in the past (though I am getting better).