This is what I just took out of the oven:
I knew something was wrong this morning when I checked the dough and it hadn't grown much and was really runny. I've seen enough cooking shows to know what dough looks like before you cook it . . . and this was definitely NOT it. I did what I always do when I don't know something: I Googled. And through Google decided that because it was particularly cold overnight (and the landlord hasn't seen fit to turn the heat on yet), that the slow rise was due to lack of heat. I decided to turn my space heater on and let the dough rise a few extra hours . . . which helped a bit in the runny department, and further Googling revealed many reviews of the No Knead Bread recipe saying that it was "very wet," so I decided to try to bake it anyway even though it looked really terrible.
After baking for 30 minutes the dough was still practically flat so I knew it had failed and started Googling yet again. Which is when I realized I used the wrong yeast! I thought that Rapid Rise yeast is the same thing as Instant Yeast, but it isn't. I am fairly certain that's why I ended up with something that looks more like focaccia than crusty Italian bread.
I cut into it (it is very solid and almost impossible to slice through the bottom crust) to taste and it actually tastes fine, which is really surprising given how it came out. Upon touching the inside I also realized it's undercooked . . . which led to more Googling and the discovery that I had misread the recipe and set the oven for 400 degrees instead of 450. Which I'm sure didn't help matters any.
I'm trying again tomorrow. Stay tuned.
(PS - This post is meant to add to the collective online wisdom so that future equally clueless bakers Googling for "why my dough didn't rise" will have even more information to work from. Gotta do my part!)