It you've never opened a container of tofu in your life, it may surprise you to see this little white block swimming around in water. It's necessary to prevent your precious tofu from drying out, but you don't need it when cooking, so the first thing on your tofu-making to-do list is to drain the water.
Since tofu is like a sponge, you'll want to remove some of the water it's holding by pressing your tofu. Fold a cloth dish towel in half lengthwise, and place it on a cutting board. Place the block of tofu on one end, and fold the towel over the top of the tofu. Rest a large plate on top, and gently press down to squeeze out any excess water. Don't squeeze too hard unless you want crumbles for a tofu scramble.